Artículos

Imprimir

COLOQUIOS IA-UNAM  DE FECHAS ANTERIORES 2016 - 2017 - 2018

 


 

Fecha

miércoles 13 de Enero, 2016

Hora y Lugar

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

Ponente 

Iva Karovicova (Institute of Theoretical Astrophysics, Heidelberg) 

Título  

Infrared interferometric observations of low mass evolved stars 

 

Resumen  

 I will present an investigation of the dust formation process in the atmospheres of a sample of oxygen-rich AGB stars using spatially and spectrally resolved infrared interferometric observations. We successfully compared multi epoch observations 
 to a radiative transfer model of the dust shells, where the central stellar intensity profile is described by a series of dust-free 
 dynamic model atmospheres based on self-excited pulsation models. 
 We determined chemical composition and inner boundary radii of the dust shells.  We also estimated photospheric angular diameters of the individual stars.  

 

 

Fecha

Miércoles 20 de Enero, 2016

 

Ponente 

Mariana Espinosa (UNAM) 

Título  

El manzano de la gravitación, una guia para comunicar la ciencia a traves de las visualizaciones 

Hora y Lugar

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen  

En esta charla presentaré el Manzano de la gravitación, un árbol genealógico temporal y mapa conceptual de las teorías de gravitación desarrolladas durante el siglo XX y accesible al público en formato interactivo. El trabajo ha resultado una guía para realizar visualizaciones complementarias sobre el progreso de esta ciencia y se encuentra en sintonía con los festejos del 100 aniversario de la Teoría General de Relatividad. 

 

 Fecha

Lunes 25 de Enero, 2016

 

Ponente 

Juan Magaña (Instituto de Fisica y Astronomia de la Universidad de Valparaiso) 

Título : 

 Constricciones cosmológicas de modelos alternativos de energía oscura

Hora y Lugar

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen  

A finales de la década de los 90's las observaciones de las supernovas de tipo Ia proporcionaron la primera evidencia de la expansión acelerada del Universo. La responsible de esta aceleración cósmica es la denominada energía oscura y su naturaleza es una de las grandes interrogantes de la Cosmología y Astrofísica moderna. La constante cosmológica es el candidato más favorecido por las diversas observaciones cosmológicas: las oscilaciones acústicas bariónicas, radiación cósmica de fondo, etc. Sin embargo, este modelo tiene algunos problemas teóricos como el problema de la coincidencia y el de ajuste fino. En este charla, abordaré diversos modelos alternativos de energía oscura (dinámica, interactuante, Cardassiano, etc. ) y sus constricciones obtenidas con los datos observacionales más recientes.

 

 

 

 


 Fecha

Miércoles 27 de Enero, 2016

 

Ponente 

Julio A. Fernández (Depto. Astronomía, Universidad de Montevideo) 

Título  

Objetos en transición o híbridos cometa-asteroide en la vecindad de la tierra 

Hora y Lugar

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen  

Se discutirán las características dinámicas y físicas de los objetos que se acercan a la Tierra (NEOs), prestando particular atención a aquellos con actividad baja o residual. Se encuentra que muchos objetos entre los NEOs comparten características de cometas y asteroides. Se discutirá si ellos pueden ser caracterizados como objetos en transición cometa-asteroide, es decir si son cometas helados que retienen una capa de polvo aislante, o son intrínsecamente híbridos con una matriz rocosa (como los asteroides) pero conteniendo algo de hielo de agua. Aparte de la distinta proporción de hielo/roca, el cociente isotópico deuterio/hidrógeno (D/H) podría ser distinto si estos objetos se formaron en regiones más cercanas al Sol (p. ej. el cinturón de asteroides), donde el hielo de agua pudo haberse sublimado y recondensado causando un empobrecimiento de deuterio en las moléculas de agua, llevando el cociente D/H del agua en estos objetos híbridos a valores más cercanos al de los océanos terrestres. Extrapolando estos resultados al origen del sistem solar, se sugiere que estos objetos híbridos pudieron ser la fuente principal del agua terrestre. 

 

Fecha

 

Miércoles 3 de Febrero, 2016

 

Ponente 

Alejandro Baez Rubio (UNAM) 

Título  

Caracterization of the kinematics of ionized circumstellar disks and winds in Ultracompact HII regions showing maser emission at hydrogen recombination lines

Hora y Lugar

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen  

Massive stars play a key role in the Galactic evolution. However, there are important observational difficulties to study them. This is the reason why it is still under debate how they are formed and what are the physical processes affecting to their first stages of evolution. In order to unveil them, we have studied the kinematics of Ultra-Compact HII regions (UC-HII). Our studies were focused on the analysis of recombination-line emission, specially in those sources whose recombination lines are affected by maser amplification. This is motivated by the fact we can use the strong emission of these lines to perform studies with a high spectral and spatial resolution. 

In this talk I will show you some of the features of the non-LTE 3D radiative trasfer model MORELI (MOdel for REcombination LInes). This code simulates the radio-continuum and recombination line emission, both under LTE and non-LTE conditions, of UC-HII regions. We have used them to study the geometry, physical structure and kinematics of several UC-HII regions. The main results that I will present will be those obtained by the modelling of the ionized circumstellar disk and wind of the massive star MWC349A. In particular, I will show the findings suggesting that the magnetic field plays a key role in launching its wind from its circumstellar disk. 

On the other hand, I will show the modelling of other UC-HII regions where we have recently detected maser recombination lines (Cepheus A HW2, Monoceros R2-IRS2 and G35.58-0.03). Thus, I will show how the new instrumental capabilities of mm and submm instruments allow us to detect this type of line. It clearly suggests that these lines have the potential to provide important advances in understanding the processes affecting to circumstellar disk and winds around sources with dense winds.  

 

 

Fecha

Miércoles 17 de Febrero, 2016
 
Ponente 

Xavier Hernández (IA UNAM) 

Título : 
 
Existe realmente la materia obscura? 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
Assuming Newton's gravity and General Relativity (GR) to be valid at all scales leads to the ad hoc dark matter hypothesis as a requirement demanded by the observed dynamics and measured baryonic content at galactic and extragalactic scales. 
Such a component has never been observed, and decades of targeted direct search experiments have eliminated a growing number of candidates, forcing the field from the simple to the exotic to the increasingly contrived dark matter options.
Alternatively, modified gravity scenarios where a change of regime appears at acceleration scales a<a_0 have been proposed. This modified regime at a<a_0 will generically be characterised by equilibrium velocities which become independent of distance and scale with the fourth power of the total (Baryonic) matter content. 
I will review a number of predictions of such approaches across astrophysical scales, and show how recent measurements have invariably agreed with such predictions. 

 

 

Fecha

Miércoles 24 de Febrero, 2016
 
Ponente 

Juan Echevarría (IA UNAM) 

Título : 
 

A Radial Velocity Study of the Intermediate Polar EX Hydrae

 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

A study on the intermediate polar EX Hya is presented, based on simultaneous photometry and high dispersion spectroscopic observations, during four consecutive nights. The strong photometric modulation with the 67-min spin period is clearly present, as well as the narrow eclipses, associated with the orbital modulation. Since our eclipse timings have been obtained almost 91,000 cycles since the last observations, we present new linear ephemeris, although we cannot rule out a sinusoidal variation suggested by previous authors. The system shows double-peaked H alpha, H beta and He II 4686 emission lines, with almost no other lines present. As H alpha is the only line with enough S/N ratio we have concentrated our efforts in this study, to obtain a reliable radial velocity semi-amplitude. From the profile of the line, we find two important components, one with a steep rise, but with velocities not larger than about 1000 km/s and another broader component extending up to 2000 km/s, which we interpret as coming from the inner disc or accretion column. A strong and variable hotspot is found and a stream-like structure is seen at times. We show that the best solution is K1 = 57 km/s from from the two emission components, which are both in phase with the orbital modulation. We remark on a peculiar effect in the radial velocity curve around phase zero, which could be interpreted as a Rositter-MacLaughlin-like effect, which has been taken into account before deriving K1. This value is now compatible with the high-resolution values found in the ultraviolet and X-ray. Using an inclination angle of i = 78 degrees and a $K2 = 432 km/s semi-amplitude from published values, and assuming that these values reflect the motion of the binary components, we find: M(wd) = 0.78, M(rd) = 0.10 solar masses and a separation of the binary a = 0.67 solar radii. Doppler Tomography has been applied, and we have constructed six Doppler tomograms for single orbital cycles spanning the four days to support our conclusions.We discuss our results and compared them with current models of EX Hya.

 

Fecha

Miércoles 2 de Marzo, 2016
 
Ponente 

Julio Clemente (IA-UNAM) 

Título 
 
¿Qué es el supercómputo? El supercómputo como herramienta de la ciencia.

 

Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
En la presente plática, se abordará en forma general el supercómputo, qué es, y como éste es una herramienta fundamental para la evaluación de modelos numéricos y simulaciones de gran escala, que sirven de apoyo a los científicos en investigaciones complejas y de difícil experimentación.
 
Además, al final se comentarán esquemas para el fomento y uso del supercómputo dentro del Instituto de Astronomía de la UNAM.

 

 

Fecha

Miércoles 9 de Marzo, 2016
 
Ponente 

Marco Antonio Muñoz Gutiérrez (IA-UNAM) 

Título 

 

Origin and Evolution of Debris Discs in the Solar System and Beyond

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Circumstellar debris discs are the remnants of the original protoplanetesimal disc from which planets form. In the solar system, the asteroid belt and the Kuiper belt constitute the evolved stage of the original leftovers of planet formation. Their current orbital properties provide some evidence of the early evolution of the solar system, suggesting for example, that giant planets did not form in their current positions but migrated with the help of the planetesimal disc. A review of the early evolution of the solar system will be presented. In addition to the debris disk, also leftovers, are the dwarf planets, whose influence on the secular evolution of debris discs has been commonly underrated. We present some novel results that show how a reasonable number of dwarf planets embedded in a debris disc could strongly affect its global properties (e.g. increasing dust production and the cometary injection rate to the inner part of a planetary system).

 

 

Fecha

Lunes 14 de Marzo, 2016
 
Ponente 

Eric Martinez García

Título 
 

Resolved maps of Stellar Mass from iterative Bayesian marginalization of SPS models

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Stellar masses of galaxies are frequently obtained via SPS fitting to observed photometry, or galaxy spectra. "State of the art" methods resolve spatial structures within a galaxy to asses the total stellar mass content. In comparison to unresolved studies, resolved methods yield higher fractions of stellar mass for galaxies. In this talk we will demonstrate that current methods commonly deliver biased resolved spatial structures. We will discuss the cause of this bias, an introduce a new method, based on Bayesian statistics, aimed to mitigate the bias. We applied this method to M51, and a pilot sample of spiral galaxies. We will compare quantitatively the application of both methods and discuss the results.

 

 

Fecha

Miércoles 16 de Marzo, 2016
 
Ponente 

Anna Lia Longinotti (INAOE) 

Título : 
 
Feedback in a Seyfert Galaxy produced by a multi-component X-ray ultra-fast wind: the case of IRAS17020+4544

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

The effect of AGN winds on the larger scale environment, which is commonly referred to as “AGN feedback”, has far-reaching effects on the evolution of the host galaxy properties. For this reason, quasar feedback has been extensively postulated as a fundamental mechanism for regulating the relation of supermassive black holes with their host galaxies. The recent reports of sub-relativistic X-ray winds in very bright quasars corroborates the role of highly ionized accretion disc winds as a source of feedback. I will report on the discovery of an ultra fast outflow with a very complex ionization and velocity structure that was never observed before. The wind is detected at X-ray high spectral resolution in XMM-Newton data of the Narrow Line  Seyfert 1 Galaxy IRAS17020+4544. A series of medium and low-ionization absorption lines trace five outflow components with velocities between 0.08-0.11c with an unprecedented wide range of associated column densities and ionization levels. Ongoing work on radio observations confirms the presence of outflowing material on a scale of about 10 pc with a speed lower than ∼0.2c, potentially in good agreement with the X-ray velocities. The presence of the radio jet/outflow suggests that the wind may be magnetically driven or produced by the interaction of the radio jet with the surrounding material. It is estimated that at least one of the X-ray outflow components may carry sufficient energy to substantially suppress star formation, and heat the gas in the host galaxy. All evidences for black hole feedback so far have been found in very bright quasars, powered after major merging processes. IRAS 17020+4544 represents therefore an interesting exception, being  a typical Seyfert Galaxy with moderate luminosity and spiral morphology. 

 


Fecha

Miércoles 30 de Marzo, 2016
 
Ponente 

J. Walcher (AIP Postdam) 

Título : 
On the velocity function and enrichment histories of galaxies 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
Abstract: In this talk I will present two recent results obtained in my group. (1) The luminosity function, i.e. the number of galaxies per unit volume as a function of luminosity, is a famous and well studied fundamental oservable. The velocity function, i.e. the number of galaxies per unit volume with as a function of circular rotation velocity, is equally important — one may even say it is more fundamental as the ciruclar velocity relates more directly to mass than the baryonic luminosity. I will present the first measurement of the velocity function from a combination of HIPASS and CALIFA data. (2) The “stellar enrichment history” of a galaxy is a four-dimensional space occupied by the stellar populations in each galaxy and spanned by the parameters age (i.e., time elapsed since formation of those populations), [Fe/H], [α/Fe] and the mass (or luminosity) contribution of these stars. In the “era of Gaia”, the enrichment history of the Milky Way is being studied in great detail. I will present our efforts to develop a technique that will allow to study enrichment histories for large samples of galaxies from their integrated spectra, essentially providing a benchmark for the Milky Way. I will present fossil record evidence that late mass assembly in early-type galaxies is dominated by accretion. I will also present surprising similarities in the self enrichment histories of massive early type galaxies and the Milky Way and how we can use those to derive the delay time distribution of Supernovae Ia. 

 

 

Fecha

Miércoles 6 de Abril, 2016
 
Ponente 

Gloria Koenigsberger  (Instituto de Ciencias Físicas, UNAM, Campus Cuernavaca) 

Título
 
El Instituto de Astronomía y la Introducción de Internet en México

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

La primera conexión de México a Internet se logró con un enlace satelital entre el National Center for Atmospheric Research (NCAR) an la Ciudad de Boulder y el Instituto de Astronomía de la UNAM, en Ciudad Universitaria. Del lado mexicano, la UNAM financió la compra e instalación de sus estaciones terrenas. Del lado norteamericano, el financiamiento provino de la National Science Foundation (NSF) y la NASA. El satélite utilizado fué el Morelos I. Nuestro enlace a NCAR nos permitió accesar la red NSFNET, cuyos nodos principales estaban asociados a los 5 centros de supercómputo financiados por la NSF, y a la red SPAN, operada por la NASA. El enlace de la UNAM a Internet se inauguró en la primera semana de septiembre de 1989, constituyendose el IAUNAM en el primer nodo oficial de Internet en México, gracias al uso de los protocolos de telecomunicaciones TCP/IP. Poco después, se inauguraron enlaces similares a los polos de desarrollo científico de la UNAM en Ensenada y Cuernavaca, y al Observatorio Astronómico Nacional en San Pedro Mártir. En esta presentación haré un recuento de los sucesos, entre ellos la explosión de la SN1987A, que impulsaron nuestro ingreso al mundo moderno de las telecomunicaciones.

 


 



Fecha

Viernes 8 de Abril, 2016
 
Ponente 

Iván Lacerna (PUC-Chile, MPIA-Alemania)

Título : 
 

Isolated elliptical galaxies 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
I will present a sample of nearby isolated elliptical galaxies, whose physical properties are compared with elliptical galaxies located in a high-density environment such as the Coma supercluster. The aim is to probe the role of environment on the morphological transformation and quenching of elliptical galaxies as a function of mass. I will show that the processes of morphological transformation and quenching seem to be in general independent of environment since most of the elliptical galaxies are "red and dead", although the transition to the red sequence should be faster for isolated ellipticals. Furthermore, the isolated environment seems to favor the formation of two populations of ellipticals that are not observed in the Coma supercluster, such as blue star-forming galaxies and recently quenched elliptical galaxies. I will discuss the nature of the particular set of blue and star-forming isolated ellipticals identified here. 

 

Fecha

Miércoles 13 de Abril, 2016
 
Ponente 

Leticia Carigi  (IA-UNAM) 

Título
 
Nuevo Programa de Posgrado en Astrofísica de la UNAM
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Presentaré las principales características del Plan de estudios de la Maestría y el Doctorado en Astrofísica
que se implantará en el semestre 2017-1 (agosto-diciembre 2016).

Hare incapie en las modificaciones mas relevantes de ambos planes de estudios: 1) Maestria: requisitos de ingreso y modalidades de graduación. 
2) Doctorado: Requisitos de ingreso. 

 

 

Fecha

Miércoles 20 de Abril, 2016
 
Ponente 

Edoardo Tescari  (University of Melbourne) 

Título
 
Galactic outflows at low redshift: EAGLE simulations vs SAMI observations
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

I will present the results of the joint SAMI-EAGLE project on outflows I lead at the University of Melbourne. We use the highest resolution EAGLE cosmological simulations to study incidence and properties of supernova-driven winds ejected from galaxies on the main sequence. We produce synthetic SAMI observations of outflows that we compare directly with real data. While winds are observed in only a fraction of SAMI galaxies, they appear ubiquitous among simulated star forming objects. The velocity dispersion distribution is only weakly dependent on galactic properties (e.g. stellar mass and sSFR). I will present additional quantitative analyses and discuss how these results provide important constraints to ongoing and future IFS surveys.

 


Fecha

Viernes 22 de Abril, 2016
 
Ponente 

Metin Ata (AIP, Potsdam) 

Título

The clustering of galaxies in the SDSS-I I I Baryon Oscillation Sp ectroscopic Survey: light-cone phase -space reconstruction of the large scale dark matter density field with CMASS galaxies in Data Release 12
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

I present a Bayesian phase space reconstruction of the cosmic large-scale matter density and velocity field from the SDSS-III Baryon Oscillations Spectroscopic Survey
Data Release 12 (BOSS DR12) CMASS galaxy clustering catalogue. We rely on a l a redshift dependent power-law galaxy bias including a growth factor to relate the density field at a given redshift to the galaxy distribution.We derive an expression for the real space redshift dependent galaxy bias, which needs to be corrected with one factor to account for nonlinear deviations. Our approach has thus only one parameter, assuming a given ΛCDM cosmology, and a given mesh resolution in the range of 6-10 -1 Mpc, the smallest scales at which our models are accurate. In particular, we use a Gibbs sampling approach, implemented in the argo code, to iteratively reconstruct the dark matter density field and the coherent peculiar velocities of individual galaxies. In each iteration we obtain distance estimates for each galaxy, correcting hereby for coherent redshift space distortions, as a function of redshift. This permits us to assume an isotropic power spectrum in the real-space cosmic density field reconstruction at a reference redshift, which is obtained using Hamiltonian sampling. Our tests relying on accurate N-body based mock galaxy catalogues, show unbiased real space power spectra of the nonlinear density field up to ∼ 0.Mpc − 1, and vanishing quadrupoles down to ∼ 15 − 1 Mpc.

 

Fecha

Miércoles 27 de Abril, 2016
 
Ponente 

Antonio Marinelli (Universidad de Pisa, Italia)

Título

 Interpretation of astrophysical neutrinos observed by IceCube experiment
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

In the last years the IceCube collaboration collected the largest astrophysical neutrino sample ever obtained up to PeV energies. The investigation of the origin of these events excites the astroparticle community and several hypotheses are now under debate. Here we present a possible theoretical scenario to explain the measured astrophysical neutrino flux. In particular we introduce a comprehensive model of radially-dependent cosmic-ray transport to describe the diffuse galactic neutrinos and we add an extragalactic component following the IceCube analysis. We also review the possible sources of the extragalactic neutrinos. Moreover we discuss a novel upper limit obtained with ANTARES observations for the inner galactic plane emission and the perspectives of a forthcoming combined analysis between the South Pole and the Mediterranean observatories.

 

 

 

Fecha

Lunes 2 de Mayo, 2016
 
Ponente 

Gerhard Hensler (Dept. of Astrophysics, University of Viena)

Título

Tidal-tail dwarf galaxies - formation, evolution, and survival

 
Hora y Lugar
11:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Within the hierarchical structure-formation scenario in cosmology today’s massive galaxies are assumed to form from the accumulation of smaller, gas-rich cosmological “building blocks”. In close encounters of massive galaxies tidal forces extract gas and stars to extended tidal arms. The gas clumps dissipatively to multiple self-gravitating and star-forming fragments which resemble young newly formed dwarf galaxies denoted as Tidal Dwarf Galaxies (TDGs). From the galaxy merger rate and from observable bright TDGs it can be concluded that their production may provide an important contribution to the faint end of the galaxy luminosity function. 

Due to their different regimes in phase space, TDGs' low gravitation can merely acquire Cold Dark Matter (CDM) from the massive galaxies and, therefore, not be gravitationally supported by DM halos. Since TDGs experience active star formation, the questions arise, whether TDGs can survive the stellar energy feedback, which TDG fraction dissolves from the major galaxies as free-floating DGs, which falls back to the parent galaxies, and which stay bound on orbits around the mature galaxies.  

By means of detailed chemo-dynamical simulations of TDGs we follow their evolution from their formation in tidal arms and investigate their survival as well as how and which processes affect their evolution. We also address the fundamental question of their observable identification as TDG survivors, which structural and chemical signatures develop to distinguish tidally formed DM-free DGs from 'classical' ones. We also find variations of the star formation from very low to significantly higher rates triggered by means of compression caused by gasdynamics and by tides. At high star-formation rates, surprisingly none of the models is disrupted by extreme stellar feedback, while also observed low rates indeed question the formation of a fully populated stellar initial mass function. Model TDGs are studied with respect to their star-formation history, stellar feedback, chemical abundances, and internal kinematics. 

 

   

 

Fecha

Lunes 2 de Mayo, 2016
 
Ponente 

Ewine F. van Dishoek (Leiden Observatory, The Netherlands) 

Título : 
 
Zooming in on the planet-forming zones of disks: Sweet results from ALMA

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Protoplanetary disks are the birthplaces of planets, but the spatial resolution at long wavelengths has so far been insufficient to resolve the critical 5-30 AU region. ALMA now allows us to zoom in to nearby disks and determine the physical and chemical structure associated with planet formation. This talk will provide an overview of recent work on observations and models of protoplanetary disks around young stars in various stages of evolution. Early ALMA results include evidence for rotationally supported disks in the deeply embedded stage, the detection of organic molecules (including sugar) and water in forming disks, and the first images of the CO snowline in mature disks.

Special attention will be given to transitional disks, which are a subset of disks with evidence for sharp-rimmed cavities (gaps or holes) in their inner part but with otherwise normal outer disks. These disks are called 'transitional' because they are thought to represent the evolutionary phase from the gas-rich protoplanetary disk to the gas-poor debris disk stage. They are the best candidate sources for harboring just-formed giant planets. ALMA allows imaging of both the gas and dust in these disks, with gas cavities found to be significantly smaller than those of the dust, providing constraints on the properties of the young planets. The surprising discovery of huge asymmetric dust traps ('planetesimal or Kuiper-Belt factory') will be highlighted.

 

 


 

Fecha

Miércoles 4 de Mayo, 2016
 
Ponente 

Sebastian Sánchez (IA-UNAM) 

Título : 
CALIFA DR3, características de los datos y abundancia de oxígeno

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
En el presente coloquio presentamos las características principales de la tercera distribución de datos del proyecto CALIFA, incluyendo las propiedades de la muestra, la calidad de los datos y como acceder a los mismos. Finalmente presentamos los principales resultados
sobre las propiedades de la abundancia de oxígeno en dichas galaxias  recientemente presentados en la conferencia realizada en Cozumel, y
su comparación con datos de otros surveys.

 

 

 Fecha

Miércoles 11 de Mayo, 2016
 
Ponente 

Emilio Tejeda  (IA-UNAM) 

Título
 
Simulaciones relativistas de disgregación estelar por las fuerzas de marea de agujeros negros supermasivos
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

La disgregación de una estrella causada por las fuerzas de marea de un agujero negro nos ofrece una ventana única para estudiar la mayor parte de la población de agujeros negros supermasivos que de otra manera se encuentran en una fase inactiva. Una fracción importante de este tipo de encuentros tiene lugar dentro de un régimen donde los efectos debidos a la relatividad general son importantes. En esta plática, presentaré los resultados de simulaciones numéricas recientes que modelan un evento de este tipo de principio a fin. Para esto, dividimos la simulación en dos pasos: la primera fase de aproximación y disgregación la simulamos con un nuevo código SPH relativista (lagrangiano), la siguiente fase de retorno y ensamblado de un disco de acreción la estudiamos con un código euleriano de magneto-hidrodinámica relativista. Durante la plática discutiré en particular el papel que juegan los efectos relativistas en disipar energía, formar el disco de acreción y controlar el flujo de masa hacía el agujero negro.

 


Fecha

Jueves 12 de Mayo, 2016
 
Ponente 

Itziar Aretxaga  (INAOE) 

Título
 

Galaxias gigantes en construcción a z>2

 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Se muestran los censos del cielo extragaláctico trazados por diversos telescopios, entre ellos el Gran Telescopio Milimétrico Alfonso Serrano (GTM), tanto en campos sin sesgo como en campos amplificados por efecto de lentes gravitatorias, con el objetivo de conocer cómo se formaron y evolucionaron las galaxias gigantes. Las galaxias lejanas encontradas, con brotes de formación estelar entre 100 y 1000 veces más virulentos que los de la Vía Láctea, muestran un panorama de rápido crecimiento y agrupamiento de estructuras a alto corrimiento al rojo, pero con eficiencias de formación estelar similares a las del universo más cercano.

 

 


Fecha

Miércoles 18 de Mayo, 2016
 
Ponente 

Roberto Galvan Madrid  (IRyA, UNAM) 

Título
 
Characterizing the Formation of the Most Massive Star Clusters in the Milky Way 
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
We summarize our comprehensive gas surveys of some of the most luminous (Lbol 1e5 to 1e7 Lsun), deeply embedded (optically obscured) star formation regions
in the Milky Way, which are the local cases of massive star clusters and/or associations in the making. Our approach emphasizes multi-scale,
multi-resolution imaging in dust and free-free continuum, as well as in molecular- and hydrogen recombination lines, to trace the multiple gas
components from < 0.1 pc (core scale) all the way up to the scales of the entire giant molecular cloud (GMC), or ~ 100 pc. We highlight our results on
W49A, the most luminous Galactic star formation region (Lbol ~ 2e7 Lsun), which appears to be forming a young star cluster (or a binary star cluster)
with M_star ~ 1e5 Msun that may remain bound after gas dispersal. We also highlight our recent result on the G33.92 region (Lbol ~ 3e5 Lsun), where ALMA
mapping reveals that the cluster-forming accretion flow is arranged in a fragmented spiral-like structure from clump to core scales. Preliminary
results in a handful of other regions will be shown.

 

Fecha

Miércoles 25 de Mayo, 2016
 
Ponente 

Francisco Ruiz Sala  (IA-UNAM) 

Título
 
Introducción a la seguridad de la información 
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

 La seguridad en la información no debe confundirse con seguridad informática. Se entiende por seguridad informática al conjunto de normas, procedimientos y herramientas, que tienen como objetivo garantizar la disponibilidad, integridad, confidencialidad de la información que reside en un sistema. Esta información tiene vulnerabilidades o riesgos y también esta expuesta a amenazas. 

Amenaza: Una amenaza a un sistema informático es el peligro que siempre esta latente. Es decir, las amenazas están presentes y se deben reducir al mínimo. 

Riesgo: El riesgo es la posibilidad de que un daño se produzca. Esto no es otra cosa que la probabilidad de que ocurra  la amenaza, el riesgo se utiliza sobre todo el análisis de riesgos de un sistema informático y esté permite tomar decisiones para proteger mejor al sistema de información. 

La información almacenada en equipos de computo puede llegar a ser invaluable e irreemplazable, por tanto la integridad, disponibilidad y confidencialidad son críticas en el manejo de la información. 
Del mismo modo hoy en día el el acceso a Internet es indispensable para poder manejar la información, lo cual aumenta el riesgo. 
En esta platica se pretende conocer los riesgos y la forma de evitarlos para evitar que  la información no sea perdida, alterada y/o revelada cuando esta no tiene este fin. 

 


Fecha

8 Junio, 2016

 
Ponente 

Francesca Figueras (Institute of Cosmos Science, University of Barcelona, IEEC)

Título

 The Gaia mission, two years of successful scientific operation
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
The high quality astrometric and photometric data already collected by Gaia during these almost two years of successful scientific operation allow us to anticipate that, in few years, Gaia will revolutionize our understanding of the Milky Way and its surroundings. In this talk I will shortly describe the mission status and the contents of the first and end-of-mission Data Releases, expected for September 2016 and 2022. More in detail, we will quantify the expect accuracy in position, velocity and astrophysical parameters of some key tracers of dynamics of the thin and thick discs of the Milky Way. 

The first Gaia Data Release (Gaia-DR1, September 2016) primes the pump and paves the way for a new golden age of the galactic astronomy. We expect Gaia-DR1 will provide us new parallaxes and proper motions for about two million well-behaved Tycho-2 stars. This TGAS (Tycho-Gaia Astrometric Solution) catalogue is being obtained using the first year of Gaia data and Tycho positions as priors. Gaia-DR2 (summer 2017) and later on Data Releases will provide excellent astrometric parameters – parallax, positions and proper motions - for sources up to (G=20). This data combined with future radial velocity data from large on-ground spectroscopic surveys such as APOGEE (IR) or WEAVE (optical) is opening a new window to the orbital analysis of the stars placed on the galactic disc up to distances of several kiloparsecs 

 

  


Fecha

9 de Junio, 2016
 
Ponente 

Daisuke Kawata (Mullard Space Science Laboratoy, University College London)

Título

Impacts of a Flaring Disk and Radial Mixing on the Galactic Thick and Thin Disks
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

We first summarise the thick and thin disk formation scenario commonly seen in cosmological N-body simulations. As suggested in Brook et al. (2004), a hierarchical clustering scenario causes multiple minor gas-rich mergers, and leads to the formation of kinematically hot disk, thick disk population, at a high redshift. Once the mergers become less significant at later epoch, the thin disk population starts building up. Because in this scenario the thick disk population forms intensively at high redshift through multiple gas-rich mergers, the thick disk population is compact and has systematically higher [α/Fe] abundance than the thin disk population. In addition, we show that the current cosmological simulation also naturally predict that the thin disk population is flaring at the outer region. Consequently, at the high vertical height from the disk plane, the compact thick disk population (low metallicity and high [α/Fe]) is dominant in the inner region and the flaring thin disk population (high metallicity and low [α/Fe]) contributes more in the outer region. This helps to explain the positive radial metallicity gradient and negative radial [α/Fe] gradient observed at the high vertical height in the Milky Way stellar disk. We then discuss how radial migration impacts the metallicity distribution of the thin disc population. We demonstrate that the flaring star forming region could be required to explain the negative vertical metallicity gradient observed in the thin disc population. 

   

 

Fecha

10 de Junio, 2016
 
Ponente 

Dr. Eugene Vasiliev (Oxford University (UK) and Lebedev Physical Institute (Moscow, Russia))

Título

Life and adventures of binary supermassive black holes
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

 I review our present understanding of the evolution of binary supermassive black holes -- how do they form, why do they eventually merge into a single black hole, and what happens afterwards, as well as discuss their possible observational signatures (gravitational-wave and electromagnetic counterparts) and perspectives of detection. 

 

 

Fecha

15 de Junio, 2016
 
Ponente 

Enrico Ramirez

Título

  
Heavy element synthesis in the Universe
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

The source of about half of the heaviest elements in the Universe has been a mystery for a long time. Although the general picture of element formation is well understood, many questions about the nuclear physics processes and particularly the astrophysical details remain to be answered. Here I focus on advances in our understanding of the origin of the heaviest and rarest elements in the Universe.

 

Fecha

22 de Junio, 2016
 
Ponente 

Gianmassimo Tasinato (Swansea University, UK)

Título

Cosmological Inflation and Symmetry Breaking
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Cosmological inflation is the best candidate available for solving the basic problems  of standard big bang cosmology, and for setting the initial conditions for  the evolution of the  observed universe. After reviewing  the basic features and predictions of the simplest models of cosmological inflation, I will discuss  a novel approach to study inflationary observables, based on the application of the concept of symmetry breaking to cosmology. I will show how such approach generalises the usual predictions of inflation, in particular for what respect the properties  of inflationary gravitational waves, with potentially interesting consequences for their future detection. 

 

 

Fecha

Miércoles 3 de Agosto, 2016
 
Ponente 

Xavier Hernández  (IA-UNAM) 

Título
 
Theoretical lower limits on sizes of ultra faint dwarf galaxies from dynamical friction
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
Dwarf spheroidal galaxies are the smallest known stellar systems where under Newtonian interpretations, a significant amount of dark matter is required to explain observed kinematics. In fact, they are in this sense the most heavily dark matter dominated objects known. That, plus the increasingly small sizes of the newly discovered ultra faint dwarfs, puts these systems in the regime where dynamical friction on individual stars starts to become relevant. We calculate the dynamical friction timescales for pressure supported isotropic spherical dark matter dominated stellar systems, yielding $\tau_{DF} =0.93 (r_{h}/10 pc)^{2}  (\sigma/ kms^{-1}) Gyr$, { where $r_{h}$ is the half-light radius}. For a stellar velocity dispersion value of $3 km/s$, as typical for the smallest of the recently detected ultra faint dwarf spheroidals, dynamical friction timescales becomes smaller than the $10 Gyr$ typical of the stellar ages for these systems, for $r_{h}<19 pc$. Thus, this becomes a theoretical lower limit below which dark matter dominated stellar systems become unstable to dynamical friction. We present a comparison with structural parameters of the smallest ultra faint dwarf spheroidals known, showing that these are already close to the stability limit derived, any future detection of yet smaller such systems would be inconsistent with a particle dark matter hypothesis. (arXiv:1605.04820, MNRAS in press)

 


Fecha

Miércoles 17 de Agosto, 2016

 
Ponente 

Beatriz Sánchez y Sánchez  (IA-UNAM) 

Título
 
Estado de avance del Proyecto FRIDA
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Frida: instrumento para el infrarrojo cercano (0.9- 2.5 µm) criogénico, diseñado para operar al límite de difracción en combinación con el sistema de óptica adaptativa del  GTC (D=10.4m), tendrá dos modos de operación: imagen directa con escalas de 0.010, 0.020 y 0.040 arcsec/pixel y  espectroscopia integral de campo (IFS) con resoluciones de R ~ 1 500, R ~ 4 000 y alta resolución espectral R ~ 30 000. La unidad integral de campo está basada en un rebanador de imagen de 30 rebanadas. Los dos modos de operación usan el mismo detector Teledyne 2Kx2K. El proyecto está en etapa de integración y pruebas  de subsistemas. En esta plática se presenta un resumen de su diseño, la fabricación, el estado actual y algunas de las posibles aplicaciones científicas.

 

 

Fecha

Miércoles 24 de Agosto, 2016
 
Ponente 

Arturo Gomez-Ruiz  (INAOE) 

Título
 
Early Science Observations of proto-Planetary Nebulae with the Large Millimeter Telescope
 
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

I will present a 3mm spectral line survey of three proto-Planetary Nebulae (p-PN) known to present extreme high velocity outflows. We used the Redshift Search Reciever that produces in a single observation a spectrum of the 73-111 GHz frequency range. We detected from 1 up to 6 molecular species per source, suggesting a different chemistry for each indivudual p-PN. Among the molecules detected are 29SiO, SiO, HCN, SO, SO2 and 13CO. Some of these species are detected for the first time in these sources. I will show an analysis of the line emission in the context of the chemical properties observed in other astrophysical environments known to present extreme high velocity emission related with jets, such as star-forming regions. We conclude with the implications for the evolutiory schemes of evolved stars, in particular those describing the chemical evolution. 

 


Fecha

Miércoles 31 de Agosto, 2016

 
Ponente 

Mariana Vargas Magaña  (Instituto de Física - UNAM) 

Título
 
Decrypting the Universe with Galaxy Surveys (BOSS, eBOSS, DESI)
 
Hora y Lugar
11:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
Cosmic acceleration is one of the most important issues to be explored by modern observational cosmology. Cosmic acceleration can be explained by either modifying General Relativity on cosmological scales, or within the framework of the standard cosmological model this implies that ~70 per cent of the Universe is dominated by a new component called “dark energy” with the unusual physical property that opposes the attractive force of gravity. I will present the final  results of the Baryon Oscillation Spectroscopic Survey (BOSS) that uses the baryon Acoustic Oscillation to extract information that enables to constraint the cosmology. The BAO feature corresponds to the maximum distance travelled by acoustic waves in the matter-radiation fluid during the period from matter/radiation equality to their decoupling at z~1100 and then stretched by expansion of universe. This feature can be seen as a standard ruler allowing us to study the history of the expansion of the Universe and infer cosmological information. I will also briefly introduce eBOSS , an ongoing  program of SDSS-IV and DESI the next generation survey, both of them  devoted to explore the mysteries of dark energy by analyzing the large scale structure of the Universe.

 

Fecha

Miércoles 31 de Agosto, 2016

 
Ponente 

Dra. E. Martha Pérez Armendariz  (Departamento de Biología Celular y Tisular, Facultad de Medicina, UNAM) 

Título
 
Contribuciones del Grupo Mujer y Ciencia de la UNAM a la incorporación de la perspectiva de género en la Ley de Ciencia, Tecnología e Innovación de México.
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

 

El movimiento de género en la ciencia en México se inició a principios de los 80, cuando un grupo de estudiantes del doctorado del área biomédica en el Centro de Investigación y Estudios Avanzados (CINVESTAV) del Instituto Politécnico Nacional (IPN), fundamos las primeras agrupaciones de mujeres en la ciencia en México. Entre estas la Asociación Mexicana de Mujeres Científicas (AMMEC). La AMMEC impulsó a través de diferentes acciones el surgimiento de grupos afines en diferentes instituciones de educación superior de México. Entre éstos, en la Universidad Nacional Autónoma de México (UNAM), en el 2006, en la cual, fundamos el Grupo Mujer y Ciencia, UNAM (GMC-UNAM), cuyo objetivo principal es crear políticas públicas con perspectiva de género que contribuyan al fortalecimiento científico de México. En esta presentación resumiré las principales contribuciones del GMC-UNAM, entre éstas: A) El desarrollo las primeras mesas de análisis con perspectiva de género de la política de Ciencia Tecnología e Innovación en México, B) La generación en el 2007 de la propuesta de incluir la perspectiva de género (PEG) en la Ley de Ciencia, Tecnología e Innovación de México (CTI) tanto en la comunidad científica como el Congreso Federal; misma que continuamos impulsando hasta su aprobación por el Senado en el 2013. C) Impulsamos el avance en la reglamentación de la PEG en la CTI, a través de emitir recomendaciones (~80) con perspectiva de género en los dos Encuentros Nacionales de Género y ciencia (ENGyC) realizados en el 2013 y 2015 convocados por el FCCyT con el apoyo del CONACYT. D) Recomendamos el reconocimiento del campo de ciencia y género, en todas las áreas de las ciencias por el Sistema Nacional de investigadores (SIN), así como la creación de un sub-comité de género para la evaluación de la productividad respectiva; éstas últimas, en el segundo ENGyC 2015 que co-organizamos con el FCCyT, expert@s de género de la UAM, IPN, y la FEMU. E) Hemos presentado y analizado estas propuestas en congreso internacionales, y finalmente, pero no menos importante F) Hemos desarrollado un modelo para divulgación las aportaciones de las investigadoras de la UNAM, los “Simposios Ciclos Mujer y Ciencia, UNAM”, que hemos realizado en los últimos 10 años y cuya práctica tiende a la generalización en nuestra máxima casa de estudios, impulsando importantemente la visibilidad de sus científicas. En esta charla se presentará una selección de estas políticas públicas con PEG, así como algunos proyectos en perspectiva. AGRADECIMIENTOS: Facultad de Medicina y Química de la UNAM, Instituto de Astronomía, Instituto de Matemáticas, UNAM, FCCyT, CONACyT.

 

 

Fecha

Miércoles 7 de Septiembre, 2016

Ponente 

Leticia Carigi  (IA-UNAM) 

Título
 
Mecanismos de ingreso al Doctorado en Astrofisica en las actuales Normas Operativas
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
Explicaré los nuevos requisitos de ingreso al Doctorado, como se aplicaron en esta primera ocasión y los resultados obtenidos de la misma.
Mencionaré algunas modificaciones propuestas, hasta ahora, y cuales podrían ser viables dentro de la legislación universitaria y del espíritu que motivó el nuevo plan de estudios.
El Comité Académico recibirá, con todo gusto, planteamientos constructivos. 

 


Fecha

 Jueves 8 de Septiembre, 2016 

Ponente 

Dr Santi Roca Fabrega del Instituto Racah  (Universidad Hebrea de Israel)

Título
 
Circumgalactic Medium (CGM): what simulations can do for you (and you for simulations)
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

One of the most challenging topics on galaxy formation and evolution astrophysics, both in observations and simulations, is the understanding of the circumgalactic medium formation and its properties.

I will give a wide overview of the status of CGM studies. I will also show how observations, simulations and theoretical approaches can help each other to, at once, get a better understanding of the CGM and of the galactic feedback processes needed to generate realistic galaxies using simulation techniques.   

 

 Fecha

Miércoles 14 de Septiembre, 2016

 Ponente 

Urania Ceseña Borbón   (IA-E) 

Título
 
Sistema REGSOL (Registro de Solicitudes "OnLine")
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 Con el objetivo de simplificar, mejorar y evitar redundancias en el proceso de solicitudes de los académicos ante la CADE y el CI se ha desarrollando una implementación "online" de nuestras solicitudes ante tales instancias. El sistema llamado REGSOL (Registro de Solicitudes en linea), permite mediante  solo una captura generar casi automáticamente los
productos requeridos : a) la Solicitud Formal hacia la CADE/CI de la petición, b)el formato que se presentara a Contabilidad para la solicitud de los recursos en caso de que la solicitud sea Viaje, c)el Citatorio y d) El acta de la reunión.

 

 Fecha

Miércoles 21 de Septiembre, 2016

 Ponente 

Claudio Maccone   (Director for Scientific Space Exploration, Int´l Acad. Astronautics, Chair of the SETI permanent Committee of the IAA) 

Título
 
Astrobiology, Mathematical History, and Evo-SETI Theory
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
The evolution of life on Earth over the last 3.5 billion years was recently re-written into a mathematical form by this author as Evo-SETI (Evolution and SETI) Theory. It merges Darwinian Evolution and SETI into a small set of statistical equations based on the lognormal probability density and the stochastic process called (improperly) Geometric Brownian Motion (GBM). It turns out that each Species of Darwinian Evolution is represented by a b-lognormal, i.e. a lognormal in time starting at the time b. Similarly, each Historic Civilization is a b-lognormal in time, and all these b-lognormals have the same exponential envelope (Peak-Locus Theorem). Finally, the Shannon ENTROPY of each b-lognormal gives the MEASURE of its evolution, whether biological evolution for the Species or technological evolution for the Civilizations. This allows for the precise calculation of the INFORMATION GAP between either the Species or the Civilizations: for instance, the entropy difference between Aztecs and Spaniards in 1519 was 3.85 bits per individual, meaning that each Spaniard was 3.85 bits MORE KNOWLEDGEABLE than an Aztec, on the average. 

 

Fecha

Miércoles 28 de Septiembre, 2016

 
Ponente 

Gloria Koenigsberger  (Instituto de Ciencias Fisicas, UNAM, Mexico) 

Título
 
HD 5980: Candidato progenitor de SNIIb/IIn
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

Sabemos que las estrellas masivas (>20 Mo) mueren en un fenómeno tipo supernova, pero aún desconocemos en detalle muchos de los procesos que culminan en esta explosión y desconocemos las características observacionales de sus progenitores directos. Por ejemplo, se han observado varias explosiones supernova en galaxias remotas que han sido precedidas pocos años antes por eventos eruptivos del tipo Variable Azul Luminosa (LBV por sus siglas en Inglés), sugiriendo que algunas LBVs podrían ser progenitoras directas de SN tipo IIn. Esto contradice los esquemas evolutivos actuales de estrellas masivas, los cuales predicen que después de la fase LBV la estrella debe todavía vivir otros ~10^5 años como estrella Wolf-Rayet (WR) antes de agotar su combustible nuclear. Una manera de conciliar los modelos con las observaciones es postulando que la erupción LBV y la SN ocurren en dos estrellas distintas, posiblemente ambas pertenecientes a un sistema binario.  En esta charla describiré las características de HD 5980, el único sistema (con la posible excepción de eta Carina) conocido actualmente que consiste de una binaria WR+LBV y que deberá producir una SN en un futuro cercano.  Su ubicación en la Nube Menor de Magallanes lo hace el análogo perfecto para el estudio de progenitoras de SN en galaxias de baja metalicidad.

 

Fecha

Miércoles 05 de Octubre, 2016

 
Ponente 

Simone Dichiara (Instituto de Astronomia, UNAM, Mexico) 

Título
 
Constraining the gamma-­ray burst physics by multi-wavelength data analysis
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
Gamma ray bursts (GRBs) are among the most energetic sources in the Universe. They outshine the gamma-ray sky emitting huge amount of energy in relatively short time-scales. The study of the timing properties of their "prompt" and "afterglow" emission plays a crucial role in the investigation of the central engine mechanism allowing us to inspect eventual dominant time-scales and possible periodicity. As feedback, this information allows us to put constrains on the possible emission mechanism and also on the possible nature of the progenitor. I studied both the spectral and temporal behavior of these phenomena processing the data collected by different satellites. I inspected the timing features analyzing the light curves by means the classical Fourier approach, extracting the Power Density Spectrum (PDS) and looking for possible hints of coherent (or quasi-coherent) signals. I also studied the possible links between spectral and timing properties and their implications in terms of the physical mechanism. In this presentation I will present some of the main results of this analysis.

 

Fecha

Miércoles 19 de Octubre, 2016

 
Ponente 

Gisela Ortiz (IRyA) 

Título
 
Distances and Structure of Star-Forming Regions in the Gould's Belt
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
The structure and dynamics of molecular clouds govern the star formation process as those establish both the rate and location of star formation. 
Thus, accurate determinations of the space distribution of molecular clouds are needed. Very Long Baseline Interferometry (VLBI) is a powerful tool
to study astrophysical phenomena with very high angular resolution imaging at radio wavelengths. Besides angular resolution, VLBI also offers
sub-milliarcsecond accuracy for absolute source positions. In this talk, I will introduce a long-term VLBI survey aimed at measuring accurate distances
to individual young stars in most famous clouds belonging to the Gould's Belt. In the near term, these measurements will enable us to determine the
3D structure, as well as the dynamics of each region and the large-scale relative motions of the different clouds in the Belt. I will present recent results
from this project that include the distance determination with a few percent accuracy towards Ophiuchus and Orion, and the resolution of a longstanding
debate on the distance to Serpens.
 

Fecha

Miércoles 26 de Octubre, 2016

 
Ponente 

Jorge Barrera-Ballesteros (Johns Hopkins University

Título
 
Observing and understanding the surface mass density -- metallicity relation via the SDSS IV MaNGA survey
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
I will present the latest results on the resolved stellar mass - metallicity relation ( i.e., stellar surface mass density vs. gas metallicity) for more than 500,000 spatially-resolved star-forming resolution elements (spaxels) from a sample of 653 disk galaxies included in the SDSS IV MaNGA survey. We find a tight relation between these local properties, with higher metallicities as the surface density increases. This relation extends over three orders of magnitude in the surface mass density and a factor of four in metallicity. We show that this local relationship can simultaneously reproduce two well-known properties of disk galaxies: their global mass-metallicity relationship and their radial metallicity gradients. We also find that this relation is largely independent of the galaxy's total stellar mass and specific star-formation rate (sSFR), except at low stellar mass and high sSFR, suggesting that in the present-day universe local properties play a key role in determining the gas-phase metallicity in typical disk galaxies. I will also introduce a simple yet illustrative semi-analytical leaked-box model aimed to explain this local relation as well as the localized star formation history and chemical evolution in disk galaxies. 

 

Fecha

Miércoles 9 de Noviembre, 2016

 
Ponente 

Jairo Mendez Abreu  (Universidad de Sr. Andrews) 

Título
 
 GALAXY BULGES AS TRACERS OF GALAXY FORMATION: Clues to the origin of field lenticular galaxies.

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
The relevance of galaxy bulges as central pieces in the study of galaxy formation is nowadays well settled. Bulges come in two flavours: classical and disk-like bulges. Different formation mechanisms have been proposed to explain this dichotomy and therefore
understanding their demography is of vital importance to unveil galaxy formation.

In this talk, I will present the results of a careful photometric analysis of the galaxies present in the CALIFA survey. Using the available SDSS photometry, we found a zoo of morphological structures
(single and double bars, broken exponential profiles, etc), with bulges following this diversity in terms of a wide range of masses and concentrations (i.e., Sersic index). In particular, I will focus on
the observed properties of bulges in lenticular galaxies where, by definition, they are suppose to play an important role in their evolution. Combining the photometric analysis of the galaxy bulges
with the stellar kinematic information about their rotational support (angular momentum), we suggest that lenticular bulges were mainly formed through dissipational processes at high redshift, either wet
major mergers or coalesce of giant star-forming clumps. I will discuss these results in the general context of lenticular galaxies formation.

 

 

Fecha

Miércoles 16 de Noviembre, 2016

 
Ponente 
 
Adam Popowicz (Institute of Automatic Control, Silesian University of Technology, Poland) 

Título

  
Image processing in BRITE nano-satelllite mission – how to work with extremely noisy data.

 Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
In the presentation, I will concentrate on the mission of first Polish nano-satellites – BRIghtest Target Explorer BRITE. The mission is generally assumed to be successful and allows for collecting very valuable data. However, due to the radiation problems in CCD sensors, a dedicated pipeline had to be proposed which tackled numerous problems of BRITE’s electro-optical system (hot blinking pixels, tracker instabilities, dark current artifacts etc.). The pipeline allowed for producing first scientific results of the mission. Unfortunately, when a new type of defects – charge transfer inefficiency – developed in CCDs, a new observational technique, called “chopping”, had to be implemented. In this imaging mode, the each satellite swings its orientation between two directions, so that the collected frames can be subtracted one from other producing noise-free images. The change of operation mode resulted in development of a next pipeline, which is successfully used up to this day.

 

Fecha

 Miércoles 23 de Noviembre, 2016

 
Ponente 

Ricardo Adan Cortes Martin  (IA-UNAM) 

Título
 
MoNDian dynamical modelling of the globular cluster NGC 288 including anisotropy 
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
Resumen: Observations of globular clusters in the Milky Way have shown that their stars exhibit an asymptotic limit of dispersion of velocities, always when they cross the regime of Milgrom acceleration a0=1.2x10^-10 m/s^2, which poses a challenge for newtonian gravity. Surpisingly, the low surface density globular cluster NGC 288 exhibits a constant dispersion of velocities throughout, being virtually all of it in the low acceleration regime (a<a0). We present an isothermal spherical model of the cluster, considering anisotropy (β), within a generic MoNDian scheme. By adjusting the parameters to the analitic solution of the model, we find that the best fit of the model with the observations corresponds to the completely isotropic case (β=0), and the mass-to-light ratio obtained is consistent with independent estimates for this particular object. Therefore, we show that it is possible to explain the behavior of this cluster using only a MoNDian prescription, without considering other explanations, i.e. such as dark matter, or a tidal heating.

 

Fecha

Miércoles 30 de Noviembre, 2016

 
Ponente 

Adriana de Lorenzo-Cáceres Rodríguez  (IA-UNAM) 

Título
 
First observational evidences for long-lived and growing bars 
 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

While the observational and theoretical properties of stellar bars are widely studied topics, basic questions as for how long they live or whether they are able to efficiently funnel material to galaxy centres and drive galaxy evolution remain unanswered. In this talk I will first review a not-so-popular bar-related case: ansa-barred galaxies. Ansae are handle-like structures that appear at the end of stellar bars. While they are present in a significant fraction of barred galaxies, little is known about their nature and evolution. I will explain the project we are developing at the IA aiming at studying ansae in CALIFA and MaNGA barred galaxies. Interestingly, these structures may represent the confirmation of the long-lived nature of bars. Time permitting, I will also introduce my research on multiple-barred galaxies, another interesting but not much studied case of barred galaxies that have been proposed as an efficient mechanism for the feeding of active galactic nuclei. 

 


Fecha

Viernes 2 de Diciembre, 2016

 
Ponente 

Jose Alberto López (IA-UNAM, Ensenada)

Título

Evolución cinemática del material ionizado de nebulosas planetarias 

Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
Se presentan los resultados de medir las velocidades globales de expansión de un gran numero de nebulosas planetarias que abarcan un amplio intervalo de estados evolutivos y diferentes poblaciones estelares. La muestra comprende 133 NPs del bulbo galáctico, 100 NPs del disco en estados muy avanzados de evolución, 11 NPs del halo galáctico y 15 NPs con estrellas centrales de muy baja masa y baja metalicidad, resultando en un total de 259 NPs. Los datos de espectroscopía echelle de rendija larga provienen del catálogo cinemático de nebulosas planetarias de SPM. Los resultados revelan desde una perspectiva estadística la evolución cinemática de los cascarones de material ionizado con las condiciones cambiantes de la luminosidad ionizante y viento de la estrella central como función de la tasa evolutiva determinada por la masa de la estrella central. El alto numero de objetos utilizados en este trabajo para cada uno de los grupos bajo estudio y la homogeneidad de los datos provee por primera vez una sólida referencia observacional para confrontar con las predicciones de los modelos. Este proyecto sigue en progreso y pretende medir velocidades de expansión de  unas 300 NPs adicionales con el propósito de contar con una descripción paramétrica confiable que identifique las condiciones de expansión en términos de las diferentes poblaciones estelares, morfologías, estados evolutivos y masas de la estrella central. 

 

 

Fecha

Miércoles 7 de Diciembre, 2016

 
Ponente 

Itziar Aretxaga, INAOE (Dir. Científica de TolTEC).

 

Título

TolTEC: la nueva cámara de imagen de GTM, oportunidades de explotación científica

 
Hora y Lugar
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  

TolTEC es la cámara de imagen simultánea a 1.1/1.4/2.1mm de nueva generación que se está construyendo para el Gran Telescopio Milimétrico por un consorcio de siete instituciones encabezadas por la Universidad de Massachusetts, en la que participa el INAOE. Como parte del compromiso del equipo de TolTEC se han aprobado 4 censos públicos, de legado, galácticos y extragalácticos, que previsiblemente se ejecutarán en 2019-2021. En esta reunión se describirán brevemente las características técnicas de TolTEC, las características generales de los censos de legado, y las oportunidades de explotación científica e involucración de la comunidad nacional en la definición detallada de los mismos.

Fecha:

Miércoles 18 de Enero, 2017

Ponente:

Luis Alberto Martínez Medina

 

Título:
"Imprints of Radial Migration on the MW’s Metallicity Distribution"
 
Resumen:
 
Albeit radial migration must be a ubiquitous process in disk galaxies,
its significance in the evolution of stellar discs is not always
reflected through global simple trends (e.g. a single abundance
curve). However, there are other key observables, such as the
metallicity distribution function (MDF), that may shed some light in
this matter. We argue that the shape of the MDF not only tells us
whether the stellar disc experienced radial migration, but it also
contains important clues on the structure that triggered
it. Specifically, the MDF contains information about the dynamics and
morphology of the spiral pattern (e.g. pitch angle, pattern speed). In
order to constrain the spiral parameters, we have included a detailed
recipe for the chemical tagging in our simulations; this allows us to
produce a restriction of the structural parameters of the spiral arms
in the Milky Way as well as a method to constrain chemical evolution
models towards the center of the Galactic disc, where no chemical
model provides information. We also show that a stellar disc that has
evolved dynamically and chemically can preserve a global metallicity
gradient despite of having suffered important heating and radial
migration; this means that the presence of a metallicity gradient in a
given galaxy, does not guarantee that radial mixing has not played a
role in the evolution of the galaxy.

 

Fecha

Miércoles 1 de Febrero , 2017

 

Ponente 

Patricia Tissera (Universidad Andres Bello, Chile)

 

Título

Metallicity gradients of disc galaxies in cosmological simulations 

Hora y Lugar

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen  

The chemical abundances in galaxies are key properties for the understanding of their formation and evolution. The metallicity
of the interstellar medium in galaxies is regulated by different processes during their assembly history.            
Heavy elements are synthesized in the stellar interior and ejected into the ISM by stellar winds and Supernova explosiones.
A fraction of them will be locked up into stars by ongoing star formation while other part might be expelled from the galaxies into
the circumgalactic and intergalactic medium. The chemical properties of the ISM can be also affected by gas inflows and mergers/interactions with other galaxies.
The evolution of the metallicity gradients in disc galaxies and the possible correlations with the galaxy properties
 store information on the processes that act along their evolutionary histories.
 I will talk about results on the gas-phase metallicity and stellar gradients of disc galaxies simulated within a cosmological context.
The predicted evolution of the metallicity gradients will be discussed. 

Based on on-going results and the following published results:
2016A&A...592A..93T: The stellar metallicity gradients in galaxy discs in a cosmological scenario
2016MNRAS.456.2982T: The gas metallicity gradient and the star formation activity of disc galaxies

 

Fecha

Miércoles 8 de Febrero, 2017

 
Ponente 
 
Francisco Ruiz Sala (IA-UNAM)

Título

Introducción a la seguridad de la información 

 Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 

Se entiende por seguridad informática al conjunto de normas, procedimientos y herramientas, que tienen como objetivo garantizar la disponibilidad, integridad, confidencialidad de la información que reside en un sistema. Esta información tiene vulnerabilidades o riesgos y también esta expuesta a amenazas. 

Amenaza: Una amenaza a un sistema informático es el peligro que siempre esta latente. Es decir, las amenazas están presentes y se deben reducir al mínimo. 

Riesgo: El riesgo es la posibilidad de que un daño se produzca. Esto no es otra cosa que la probabilidad de que ocurra  la amenaza, el riesgo se utiliza sobre todo el análisis de riesgos de un sistema informático y esté permite tomar decisiones para proteger mejor al sistema de información. 

La información almacenada en equipos de computo puede llegar a ser invaluable e irreemplazable, por tanto la integridad, disponibilidad y confidencialidad son críticas en el manejo de la información. 
Del mismo modo hoy en día el el acceso a Internet es indispensable para poder manejar la información, lo cual aumenta el riesgo. 
En esta platica se pretende conocer los riesgos y la forma de evitarlos para reducir el riesgo  de la perdida de información , no sea alterada y/o revelada cuando esta no tiene este fin.

 

Ponente 
 
Joseph Silk (IAP)

Fecha

Miércoles 15 de Febrero, 2017
 
Título: 
The Limits of Cosmology
 
Hora y Lugar:
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen:
 
One of our greatest challenges is understanding  the nature of dark matter. Another is the origin of the structure of the universe, and in particular the formation of the galaxies. I will describe the progress  of our search for dark matter  by direct and indirect techniques. I will describe how the fossil radiation from the beginning of the universe, the cosmic microwave background, has provided a  window for probing the initial conditions from which structure evolved and seeded the formation of the galaxies, and the outstanding issues that remain to be resolved. I will address  our optimal choice of future strategy in order to make further progress  on understanding our cosmic origins.

 

Ponente 
 
Joseph Silk (IAP)

Fecha

Jueves 16 de Febrero, 2017
 
Título: 
Galaxy Formation and Dark Matter
 
Hora y Lugar:
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen:
 
The origin of the galaxies represents an important focus of current cosmological research, both observational and theoretical. Its resolution involves a comprehensive understanding of the interplay between dark matter, star formation, galaxy dynamics, supermassive black holes  and the cosmology of the very early universe. It is a field that is largely driven by a phenomenology that depends on our accumulating data taken with the largest available telescopes, both terrestrial 
and in space,  on the most distant objects in the observable universe and on fossil signatures from our vicinity.  In this talk, I will review our current understanding of galaxy formation,  and describe the challenges that lie ahead. The second part of my talk will  review the evidence for dark matter, from both experimental and theoretical perspectives. Most dark matter probably consists of weakly interacting non-baryonic elementary particles, and I will discuss the  prospects for dark matter detection by direct and indirect techniques. I will comment on alternatives to dark matter. 
 
Fecha

Miércoles 22 de Febrero, 2017

Ponente 
 
Juan Echevarría (IA-UNAM)

Título

 El extraño caso de la Binaria Catalísmica PNV Aql

 Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
PNV es una binaria cataclísmica del tipo WZ Sge recién descubierta, que observamos durante su super erupción.El sistema exhibe propiedades mixtas de estrellas rebotadas (con secundarias marrón); los llamados superhumps, típicos de estrellas de tipo SU Uma: un período orbital muy corto de alrededor de 80 minutos; así como evidencia de una cáscara de emisión en H alfa, típica de una estrella Nova, pero que desaparece rápidamente sin mostrar luego una etapa nebular. Exponemos este extraño caso, cuya investigación está en proceso.
 
 
Fecha

Miércoles 1 de Marzo, 2017

Ponentes: 
 
Beatriz Juarez Santamaria y Alfredo Diaz (IA-UNAM)

Título

 La importancia de los Indicadores Bibliométricos en el área de Astronomía

 Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
Resumen: En la actualidad el uso de la bibliometría se ha potenciado debido al crecimiento de la producción científica que a su vez ha generado nuevos indicadores para medir los resultados de la actividad científica y tecnológica, el factor de impacto y el h-index son algunos ejemplos. Es por ello que se creó un rubro en la página de la Biblioteca del Instituto de Astronomía en donde estos datos podrán ser consultados por el usuario, además se pondrá a disposición de la comunidad del IA una herramienta diseñada por el Dr. Christophe Morisset, la cual permite obtener información del sistema Astrophysics Data System (ADS) para la elaboración del análisis de citas a través de una interfaz desarrollada por Alfredo Díaz que permitirá que el documento se pueda crear en formato PDF, PS, Latex y Word.

 

Fecha

Miércoles 8 de Marzo, 2017

Ponentes: 
 
 Christine Allen y Rafael Costero (IA-UNAM)

Título

  La Evolución Dinámica del Trapecio de Orión.

 Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen  
 
Presentamos y discutimos datos observacionales recientes sobre las velocidades transversales, las velocidades radiales, y las masas de las principales componentes del Trapecio de Orión, así como los problemas que se derivan de la duplicidad o multiplicidad de cada componente. Con los mejores valores para estos datos realizamos integraciones numéricas para simular la evolución dinámica del Trapecio. Nuestros resultados indican que el Trapecio es un sistema extremadamente jóven. También discutimos las propiedades de las binarias que se forman durante la evolución dinámica
 
 
 
Fecha

Miércoles 15 de Marzo, 2017

Ponente: 
 
 Aldo Rodriguez-Puebla (IA-UNAM)

Título

Average galaxy Star formation histories, galaxy mergers and structural properties over the last 13.3Gyrs 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 
This talk presents new determinations of the stellar-to-halo mass relation (SHMR) at z = 0 − 10 that match the evolution of the galaxy stellar mass function, the SFR − M relation, and the cosmic star formation rate. We utilize a compilation of 40 observational studies, corrected for potential biases.  Using our robust determinations of halo mass assembly from the several cosmological N-body simulations and the SHMR, we infer star formation histories, merger rates, and structural properties for average galaxies. Our main findings: (1) The halo mass M50(z) above which 50% of galaxies are quenched coincides with sSFR/sMAR~1, where sSFR is the specific star formation rate and sMAR is the specific halo mass accretion rate. (2) M50 increases with redshift, presumably due to cold streams being more efficient at high redshift while virial shocks and AGN feedback become more relevant at lower redshifts. (3) The ratio sSFR/sMAR has a peak value, which occurs around Mvir ≈ 2 × 10^11Msun . (4) The stellar mass density within 1 kpc, Σ1, is a good indicator of the galactic global sSFR. (5) Galaxies are statistically quenched after they reach a maximum in Σ1, consistent with theoretical expectations of the gas compaction model; this maximum depends on redshift. (6) In-situ star formation is responsible for most galactic stellar mass growth, especially for lower-mass galaxies. (7) Galaxies grow inside out. The marked change in the slope of the size–mass relation when galaxies became quenched, from d log Reff /d log M 0.35 to 2.5, could be the result of dry minor mergers. 

 

Fecha

Miércoles 23 de Marzo, 2017

Ponente: 
 
 Alexandre Alarie (IA-UNAM)

Título

SpIOMM and SITELLE: Wide-field Imaging FTS

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

SPIOMM and SITELLE are two wide-field Imaging Fourier Transform Spectrometer attached to the Mont Mégantic 1.6-m telescope and the 3.6-m Canada-France-Hawaii Telescope (CFHT) respectively. These instruments are capable of obtaining the visible spectrum (350-900 nm) of every source of light in a 11 arcminute field of view, with a spectral resolution from R=2 to R>104 (for low to high spectroscopic resolution).  In this talk, I will present a short description of these instruments and illustrate their capabilities to study supernova remnants such as NGC 6992, IC 443 and Cas A. 

 
Fecha

Miércoles 29 de Marzo, 2017

Ponente: 
 
 Wolfgang Steffen Burg (IA-UNAM)

Título

10 años del Laboratorio Astrofísico Virtual SHAPE

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 
Hace ya veinte años se inició el desarrollo del software SHAPE, en su versión de Fortran77, con el objetivo de construir modelos morfo-cinemáticos de nebulosas astrofísicas. Sus aplicaciones iniciales se enfocaban a las galaxias activas, pero pronto se reconoció el potencial de aplicación en el área de nebulosas planetarias y otros objetos, lo cual dió inicio a la colaboración con investigadores del OAN-Ensenada. Hace diez años iniciamos en Ensenada el desarrollo de la versión interactiva, basada en la tecnología computacional comúnmente utilizada en cine y televisión. Entonces nació lo que ahora es un complejo laboratorio astrofísica virtual interactivo con una base de usuarios internacionales. En esta plática damos una reseña de algunos de los desarrollos y resultados más importantes que se han obtenido y cuáles son los planes a futuro.
 

 

Fecha

Miércoles 5 de Abril, 2017

Ponente: 
 
 Jesus  E. Velasco (NOVA)

Título

Amenazas Cibernéticas

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

Dar a conocer las amenazas y formas de ataque que se encuentran en internet así como los riesgos inminentes, para que los usuarios puedan tomar las precauciones necesarias y estar más protegidos al navegar por internet así como saber que hacer al recibir algún correo con fines maliciosos.

  • Introducción
  •  
  • Principales tipos de Amenazas
  •  
  • Phishing
  •  
  • Malware
  •  
  • Tipos de malware
  •  
  • Ramsonware
  •  
  • ¿Cómo nos protegemos del malware?
  •  
  • Recomendaciones Generales
  •  
  • Amenazas en Redes Sociales
  •  
  • Recomendaciones Generales
  •  
  • Amenazas en Redes Wifi
  •  
  • Recomendaciones Generales

 

Fecha

Miércoles 19 de Abril, 2017

Ponente: 
 
 Enrique Vázquez-Semadeni (IRyA, UNAM)

Título

Molecular Cloud Evolution: Global Collapse, Filaments, and Clusters

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

 I will discuss the process of molecular cloud (MC) evolution,
from their formation trhough their destruction by stellar feedback. For
Solar Neighborhood conditions, MCs originate from compressive motions in
the warm medium, which produce cold, dense, and turbulent atomic clouds.
These clouds can quickly become strongly Jeans unstable as they
incorporate material by the compression, because of their low
temperature and high density. Global collapse sets in, and proceeds
hierarchically: the small-scale, large-amplitude (SS) density
fluctuations have shorter free-fall times than the large-scale, small
amplitude (LS) ones. The LS collapses culminate a few Myr later than the
SSLA ones and consist of filamentary flows that accrete onto massive
central clumps. The filaments produced by this process are consistent
with the observed properties of observed MC filaments. The SS collapses
consist of clumps that are embedded in the filaments and are falling
onto the large-scale collapse centers. The stars formed in the early,
small-scale collapses share the infall motion of their parent
clumps. Thus, the filaments feed both gaseous and stellar material to
the massive central clump. The hierarchical collapse of the cloud leads
to a hierarchical structure of the forming cluster, which naturally
reproduces the observed age and mass segregation of young clusters.

The global collapse of the clouds implies that their star formation rate
(SFR) increases with time, until the clouds are disrupted by the feedback
from newly-formed massive stars.

 
 
Fecha

Miércoles 26 de Abril, 2017

Ponente: 
 
 Luis Zapata (IRyA, UNAM)

Título

The ALMA view of the explosive outflow in Orion KL: Relics from a violent merger

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

In this talk, I will show the recent results obtained in deep ALMA observations of the explosive outflow located in the heart of the Orion Nebula, the Orion Kleinmann-Low Nebula (Orion KL). These observations revealed over a hundred arcsecond wide and tens of arcseconds long high-velocity 12CO (J=2−1) streamers that approximately point to a central region where a young stellar massive system disintegrated about 500 yrs. The kinematics and morphology of the molecular streamers confirmed the explosive nature of the outflow in Orion KL. The energetics of the explosive outflow require the formation of a binary with an AU-scale or smaller semi-major axis. This event may have led to stellar merger which powered the explosion in the gas. Finally, I will show the latest efforts to reveal more cases where possible mergers events could led explosive outflows like the one in Orion KL.

 
Fecha

Miércoles 3 de Mayo, 2017

Ponente: 
 
 Alexandre Alarie (IA-UNAM)

Título

SpIOMM and SITELLE: Wide-field Imaging FTS

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 
SPIOMM and SITELLE are two wide-field Imaging Fourier Transform Spectrometer attached to the Mont Mégantic 1.6-m telescope and the 3.6-m Canada-France-Hawaii Telescope (CFHT) respectively. These instruments are capable of obtaining the visible spectrum (350-900 nm) of every source of light in a 11 arcminute field of view, with a spectral resolution from R=2 to R>104 (for low to high spectroscopic resolution).  In this talk, I will present a short description of these instruments and illustrate their capabilities to study supernova remnants such as NGC 6992, IC 443 and Cas A.

 

 

Fecha

Miércoles 17 de Mayo, 2017

Ponente: 
Reginaldo Durazo Moreno (IAUNAM) 
 

Título

A Universal Velocity Dispersion Profile for Pressure Supported 
Systems: Evidence for MONDian Gravity across Seven Orders 
of Magnitude in Mass 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
Para cualquier teoría MONDiana de gravedad se espera un aplanamiento en las zonas externas del perfil de dispersión de velocidades a un radio característico, en donde la velocidad de aplanamiento y el radio al que aparece muestran escalamientos con la masa total del sistema. Analizando la dinámica de cúmulos globulares y de galaxias elípticas, logramos extender significativamente la diversidad de objetos astronómicos en los que ha sido probada la gravedad MONDiana. Mostramos que un perfil universal proyectado de dispersión de velocidades describe con precisión varias clases de sistemas soportados por presión, e incluso que las expectativas de gravedad extendida se cumplen a través de 7 órdenes de magnitud en masa. 
 
Fecha

Miércoles 24 de Mayo, 2017

Ponente: 
Joaquin Bohigas (IAUNAM-E) 
 

Título

Un modelito para la region mas fria del universo (natural) 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
The most striking feature of the Boomerang Nebula is a large nearly spherical cloud where the temperature is close to 2 K. At it's inner and outer boundary, this cloud is expanding at velocities close to 35 and 180 km/s. The cloud surrounds an AGB star and a smaller bipolar molecular cloud, expanding much more slowly. The ultra-cold spherical cloud has been and still is expanding into a rarefied medium, since there is no trace of a shock wave. This ultra-cold cloud is modeled using the analytical solution for a power driven expansion of a spherically symmetric cloud, followed by an adiabatic expansion phase, both into a vacuum. Assuming that the cloud is at a distance of 1500 pc, the present temperature and velocity and mass distribution profiles, are reproduced with a model where the cloud has an energy close 8.5x10^46 erg per solar mass and was ejected 1000 yr ago. In this model, the power driven phase lasts for ~ 10 yr and half of the energy is injected in less than a year. The general features of this model, are amenable with what is found in other spherical shells surrounding AGB stars, the small amount of mass lost by massive OH/IR stars and evolutionary models indicating that there may be extremely high and abrupt mass loss phases in AGB stars. The energy and timescale suggests that the ejection of the cold spherical cloud was an intermediate luminosity transient.
 
 
Fecha

Miércoles 31 de Mayo, 2017

Ponente: 
 ASTRO JAMBOREE

Título

 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

 


 
Fecha

Miércoles 14 de Junio, 2017

Ponente: 
 ASTRO JAMBOREE
 

Título

 

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 

 

 

Fecha

Miércoles 21 de Junio, 2017

Ponente: 
 Aldo Rodriguez-Puebla (IA-UNAM)
 

Título

 El coloquio en números

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 

En esta platica compartire la estadística recabada durante el ultimo año sobre los coloquios impartidos. Esta información es de utilidad para implementar posibles mejoras a la dinámica de esta actividad.
 

 

Fecha

Miércoles 16 de Agosto, 2017

Ponente: 
 
 Diego Lopez-Camara (IA-UNAM)

Título

¿Muerte de la fase de la envolvente común, producción de destellos de rayos gamma ultra largos, chorros intermitentes? Altas energías (10^51 erg) producidas mediante la interacción de un objeto compacto eyectando un chorro, dentro de una envolvente común.

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

En esta charla presentaré un escenario en el que un chorro lanzado desde un objeto compacto (OC) durante la fase de envolvente común (EC), puede producir energías y duraciones comparables a las de los destellos de rayos gamma (~51 erg durante decenas de segundos aproximadamente).  En específico, mostraré un modelo analítico mediante el cual se obtienen a grosso modo los posibles resultados dada la interacción entre un OC que se mueve a través del material de la EC y que lanza un chorro. Además, mostraré los resultados numéricos de esta misma interacción. A partir de las simulaciones numéricas (bidimensionales) no solo se confirman los resultados de la solución analítica, sino que además se obtiene más información sobre la evolución y detalles del la interacción OC-chorro-EC. Algunos de los resultados más interesantes son: que el chorro puede presentar un comportamiento intermitente, puede ser apagado, o incluso puede remover las capas externas de la EC.

 

 

Fecha

Miércoles 23 de Agosto, 2017

Ponente: 
 
 Eric Vazquez Jauregui (IF-UNAM)

Título

Cámaras de burbujas y detectores de argón para búsqueda de materia oscura

Hora y Lugar

12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen 
 

La identificación de la materia oscura es uno de los retos más importantes de la Física contemporánea. Actualmente se sabe que alrededor del 15% de la materia del Universo es materia bariónica mientras que desconocemos el 85% restante. La evidencia sobre este tipo de materia desconocida está basada en una impresionante cantidad de observaciones a diferentes escalas. Uno de los candidatos más viables para materia oscura desde el punto de vista de Física de Partículas es el llamado WIMP (Weakly Interacting Massive Particle), ya que de manera natural genera las densidades de materia oscura compatibles con restricciones cosmológicas y además surge, también de manera natural, en muchas extensiones del actual modelo estándar de la Física de Partículas. El Instituto de Física de la UNAM participa en dos experimentos con grandes posibilidades de descubrir la materia oscura, si su naturaleza es en forma de partículas débilmente interactuantes (WIMP). La colaboración PICO utiliza líquidos sobrecalentados en cámaras de burbujas para la detección de partículas; estos detectores son sensibles a interacciones WIMP­-nucleón dependientes e independientes del espín y la colaboración DEAP utiliza más de tres toneladas de argón líquido sensible a acoplamientos WIMP-nucleón independientes del espín. PICO-60 y DEAP-3600 son dos experimentos que se encuentran instalados en el laboratorio subterráneo canadiense SNOLAB, cerca de Sudbury Ontario, a 2 kilómetros bajo la superficie de la tierra, para remover los rayos cósmicos que continuamente golpean nuestro planeta. En este coloquio presentaré los resultados más recientes obtenidos con los detectores PICO-60 y DEAP-3600 en la búsqueda de materia oscura por medio de detección directa.

Ponente 
 
Manuel Peimbert Sierra (IA-UNAM)

Fecha

Miércoles 30 de Agosto del 2017
 
Título: 
50 años de inhomogeneidades térmicas en nebulosas gaseosas
 
Hora y Lugar:
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen:
 
Con motivo del 50 aniversario de la publicación del artículo de ihomogeneidades de temperatura de mi autoría, presentaré una revisión de cómo ha evolucionado el campo de las nebulosas planetarias y las regiones HII durante este periodo y cuál es la situación actual.
 
Ponente 
 
Oscar Ignacio Barragán Villanueva (U. Torino)

Fecha

Miércoles 6 de Septiembre del 2017
 
Título: 
High-precision mass and radius determination of K2 exoplanets
 
Hora y Lugar:
12:00h, Sede IA-CU
Auditorio Paris Pishmish 
 
Resumen:
 
The transit of an exoplanet in front of its host star provides us with valuable information about its size. When combined with radial velocity (RV) measurements, transit photometry gives us access to the geometry of the orbit, enabling the measurement of the true mass of the planet and its radius. Crucially, these observations yield planet densities, as well as confirming the planetary nature of systems. Densities are vital to understand planetary composition and formation, and the nature of the transition between gaseous and rocky planets. In its extended K2 mission, Kepler is surveying different stellar fields located along the ecliptic, performing 80 day long continuous observations of 10000–20000 stars per campaign. The K2 space mission is currently targeting bright stars, a definitive advantage for any RV follow-up. A significant fraction of the 100 or so transiting planets discovered by K2 have had their masses measured by ground-based RVs. Our KESPRINT consortium has characterized almost half of the K2 planets with an RV mass measurement. I will review the contribution of K2 to the field, with a particular focus on those planets for which the mass has been measured by the KESPRINT team using RV. Our family portrait includes ultra-short period super-Earths with bare rocky cores, Neptune-like planets with volatile-rich envelopes, and gaseous giant planets.
 

 

Ponente 

 

Ary Rodriguez (ICN-UNAM)

Fecha

Miércoles 13 de Septiembre del 2017

 

Título: 

 Modelos de Vientos Galácticos

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen:

 

Los brotes de formación estelar contienen cúmulos estelares jóvenes los cuales inyectan la energía suficiente para empujar parte del medio interestelar fuera de las galaxias. En algunos casos los vientos galácticos contienen una importante parte de los metales producidos por las nuevas generaciones estelares. Las regiones de formación estelar concentradas en el centro del potencial son una maquinaria importante para la pérdida y redistribución de masa y metales en este tipo de galaxias. Sin embargo, regiones de formación estelar lejos del centro del potencial pueden propiciar una importante pérdida de metales en galaxias enanas. Presentaré los resultados de modelos que cubren un gran cantidad de parámetros libres por ejemplo, índices de concentración, fracción de gas en el disco, distancia radial, energías y tamaños de los brotes, etc.

 

 

 

Ponente 

 

Tony Beasley (NRAO)

Fecha

Martes 19 de Septiembre del 2017

 

Título: 

 Frontiers of Radio Astronomy: The Next Generation Very Large Array

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen:

 

This talk will describe the current science goals, design and planning status of a future large centimeter radio array: the ‘Next Generation Very Large Array’ (ngVLA). The ngVLA is being developed to observe at wavelengths between ALMA at submm wavelengths, and the future SKA-1 at few centimeter and longer wavelengths, opening a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milliarcsecond resolution, and unprecedented broad band continuum polarimetric imaging of non-thermal processes. The current design for the array includes 10x more effective collecting area and 10x higher spatial resolution than the current JVLA or ALMA, carefully optimized for operation in the frequency range 10GHz to 50GHz, while still delivering world-leading sensitivity over the entire 1.2GHz to 115GHz spectrum. With this array, new frontiers in modern astronomy can be reached, including direct imaging and chemical analysis of planet formation in the terrestrial-zone or nearby stars, to studies of dust-obscured star formation and the cosmic baryon cycle down to pc-scales in the local Universe, and detailed imaging of molecular gas and galaxy formation out to high redshifts. Novel techniques for exploring temporal phenomena on timescales from milliseconds to years can be implemented. The ngVLA will be situated in the desert southwest of the United States, centered on the current JVLA infrastructure, with multiple antennas anticipated in states/regions adjacent to NM, and in northern Mexico. A Project Office, based at the JVLA, is working closely with the U.S. and international research community to design the array, and plan its construction beginning mid next decade. In this talk the current status of ngVLA, including science drivers, and the design and parameter space of the instrument will be presented, and the process of community studies driving design specifications are described. Recent significant NSF support has allowed commencement of a formal design & development program enabling formal concept development and technology prototyping/risk reduction before the next U.S astronomy Decadal Survey.

 

 

Ponente 

 

María de los Ángeles Pérez Villegas (IAUNAM)

 

Fecha

 

Miércoles 27 de Septiembre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Resumen:

 

Comparing data on the kinematics of the Solar neighborhood from TGAS Gaia DR1 to newly constructed made-to-measure dynamical models of the Milky Way we propose a novel explanation for the Hercules stream consistent with recent measurements of the extent and pattern speed of the Galactic bar. The model matches the 3D density of the Red Clump Giant stars (RCGs) in the bulge and bar as well as stellar kinematics in the inner Galaxy, with a pattern speed of 39 km/s/kpc. Cross-matching this model with TGAS Gaia DR1 data combined with RAVE and LAMOST radial velocities, we find that the model naturally predicts a bimodality in the U-V-velocity distribution for nearby stars which is in good agreement with the Hercules stream. In the model, the Hercules stream is made of stars orbiting the Lagrange points of the bar which moves outwards from the bar's corotation radius to visit the Solar neighborhood. This new picture of the Hercules stream naturally predicts that the Hercules stream is more prominent inwards from the Sun and nearly absent only a few 100 pc outwards of the Sun, and plausibly explains that Hercules is prominent in old and metal-rich stars.

 

 

 

Ponente: 

 

Enrico Ruiz (UC Santa Cruz, EUA)

 

Fecha:

 

Lunes 2 de Octubre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

Stellar Tidal Disruption: what can we learn and what have we learned

 

Resumen:

 

In the last several years, the disruption and accretion of stars by super-massive black holes (SMBHs) has been linked to tens of luminous flares observed in the cores of nearby galaxies. Our theoretical understanding of these tidal disruption events (TDEs), however, remains incomplete. While recent simulations have provided unprecedented detail on the dynamics of the disruption, we still do not have a good understanding of how infalling gas circularizes and accretes onto the SMBH, or how or where the thermal emission we observe is generated. The art of modeling the tidal disruption of stars by massive black holes forms the main theme of my talk. Detailed simulations should tell us what happen when stars of different types get tidally disrupted, and what radiation a distant observer might detect as the observational signature of such events.

 

Ponente: 

 

Panos Patsis ( Research Center for Astronomy and Applied Mathematics, Atenas Grecia)

 

Fecha:

 

Miércoles 11 de Octubre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

Boxy Structures in Bars

 

Resumen:

 

The orbital content of standard 3D bars, like the bar of the Milky
Way, is both regular and chaotic. Morphological features like the
peanut- and the X-shaped bulges can be reproduced in models by means
of dynamical mechanisms based on nonlinear phenomena. These dynamical
mechanisms are associated either with families of periodic orbits
belonging to the "x1-tree", or with orbits belonging to other,
recently found, families that exist in phase space at the appropriate
energies.
Besides the "traditional" method for building boxy bulges, i.e. by
using regular orbits trapped around periodic orbits, one can invoke
sticky chaotic orbits in the Inner Lindblad Resonance (ILR) regions of
the models for the same purpose. In that latter case the orbits that
build the X-shape structures are related with a particular landscape
that appears in phase space. In addition these orbits support
simultaneously boxy features also in the *face-on* projections in the
middle of the bars. In the talk I will present these new orbital tools
for building X-shaped and boxy bulges, but also boxy bars.

 

 

 

 

Ponente: 

 

Susana Biro (DGDC-UNAM)

 

Fecha:

 

Miércoles 25 de Octubre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

Ecos de Nuestro Pasado

 

Resumen:

 

Presentaré los avances en el trabajo de la organización de los documentos históricos del

Instituto de Astronomía, con especial énfasis en los audios y transcripciones de las

entrevistas que le hice a Arcadio Poveda y Rafael Costero. Mostraré los usos que se le

ha dado a dicho trabajo, así como todo lo que queda por hacer.

 

 

Ponente:  Jose Gregorio Fernandez Trincado (Universidad de Concepción, Chile)

 

Fecha:

 

Jueves 26 de Octubre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

“GravPot16, CAPOS, APOGEE-2S and Gaia: The Gold Era of large spectroscopic surveys and the new generation of dynamical models.“

 

Resumen:

 

In the first part of this contribution talk, I will briefly introduce the Milky Way modelling algorithm called GravPot16, with an emphasis on the use of data from Gaia which will provide exquisite parallaxes and proper motions for million stars, along with other complementary spectroscopic survey data like APOGEE-2 and computational modelling of Synthetic Stellar Populations. The second part, will highlight the new challenges and questions on Stellar Nucleosynthesis raised through the results of many current large-scale surveys in the Milky Way and its relation with Multiple Stellar Populations (MPs) on Galactic/Extragalactic globular clusters as unique laboratories to study the onset of chemical anomalies, as well as the key role of the APOGEE-2S survey to provide exquisite chemical abundances and radial velocities for many stars in a large fraction of Milky Way bulge globular clusters to provide important insights both on the onset of MPs in globular clusters, chemical anomalies in the field as well as the nature of the proto-galactic building blocks of the bulge. 

 

 

 

Ponente: 

 

Gagik Tovmasian (IA-E UNAM)

 

Hora y Lugar:

11:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

A new asynchronous short period polar IGR J19552+0044

 

Resumen:

 

Based on XMM–Newton X-ray observations IGR J19552+0044 appears to be either a pre-polar or an asynchronous polar.  We conducted follow-up optical observations to identify the sources and periods of variability precisely and to classify this X-ray source correctly. Extensive multicolor photometric and medium- to high-resolution spectroscopy observations were performed and period search codes were applied to sort out the complex variability of the object.We found firm evidence of discording spectroscopic (81.29 ± 0.01 m) and photometric (83.599 ± 0.002 m) periods that we ascribe to the white dwarf  (WD) spin period and binary orbital period, respectively. This confirms that IGR J19552+0044 is an asynchronous polar. Wavelength dependent variability and its continuously changing shape point at a cyclotron emission from a magnetic WD with a relatively low magnetic field below 20 MG. The difference between the WD spin period and the binary orbital period proves that IGR J19552+0044 is a polar with the largest known degree of asynchronism (0.97 or 3%). 

 

 

 

Ponente: 

Rosa Gonzalez Delgado (Instituto de Astrofisica de Andalucia, Granada, España)

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

The spatially resolved star formation history of galaxies: Implications for galaxy formation from the CALIFA survey

 

Resumen:

 

The spatially resolved stellar population content of taday's galaxies holds important information for understanding the diferent processes that contribute to the star formation and mass assembly histories of galaxies. In this talk we will present the results from the analysis of more than 400 nearby galaxies from the CALIFA survey with the goal of retrieving the spatially resolved star formation history of galaxies. Spectral synthesis is applied to the data cube to obtain the radial profiles of the intensity of the recent star formation rate, the local specific SFR, and also their time evolution. To emphasize the behavior of these properties for galaxies that are on and off of the main sequence of star formation we will discusse the results by attending to the galaxy mass and the Hubble type.

 

 

 

 

Ponente:

 

Roberto Cid Fernandes (Universidad de Santa Catarina, Florianopolis, Brasil)

 

Fecha:

 

Martes 31 de Octubre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

DIG in CALIFA galaxies

 

Resumen:

 

We use spatially resolved spectroscopy from the CALIFA survey to study the nature of the line emitting gas in galaxies of different Hubble types, focusing on the separation of star-forming (SF) regions from those better characterized as diffuse ionized gas (DIG). The diagnosis is carried out in terms of the equivalent width of Ha (W_Ha). Three nebular regimes are identified: (1) Regions where W_Ha < 3 A define what we call the hDIG, the component of the DIG where photoionization is dominated by hot, low mass, evolved stars (HOLMES). (2) Regions where W_Ha > 14 A trace SF complexes. (3) W_Ha values in the intermediate 3--14 A range reflect a mixed regime (mDIG) where more than one process contributes. This three-tier scheme is inspired both by theoretical and empirical considerations. Its application to CALIFA galaxies of different types and inclinations leads to the following results: (i) The hDIG component is prevalent throughout ellipticals and S0's as well as in bulges, and explains the strongly bimodal distribution of W_Ha both among and within galaxies. (ii) Early type spirals have some hDIG in their disks, but this component becomes progressively less relevant for later Hubble types. (iii) hDIG emission is also present above and below galactic disks, as seen in several edge-on spirals in our sample. (iv) The SF/mDIG proportion grows steadily from early to late types spirals, and from inner to outer radii. (v) Besides circumventing basic inconsistencies in conventional DIG/SF separation criteria based on the Ha surface brightness, our W_Ha-based method produces results in agreement with a classical diagnostic-diagram analysis.

 

 

 

 

 

Ponente: 

 

Marco Muñoz (IA-UNAM)

 

Fecha:

 

Miércoles 8 de Noviembre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

The long-term evolution and stability of four Saturnian small satellites with dusty arcs/rings: Aegaeon, Methone, Anthe and Pallene

 

Resumen:

 

Aegaeon, Methone, Anthe and Pallene are four Saturnian small moons, discovered by the Cassini spacecraft. Although their orbital characterization has been carried on by a number of authors, their long-term evolution has not been studied in detail so far. In this work, we numerically explore the long-term evolution, up to 105 yr, of the small moons in a system formed by an oblate Saturn and the five largest moons close to the region: Janus, Epimetheus, Mimas, Enceladus and Tethys. By using frequency analysis, we determined the stability of the small moons and characterize, through diffusion maps, the dynamical behaviour of a wide region of geometric phase space, a versus e, surrounding them. Those maps could shed light on the possible initial number of small bodies close to Mimas, and help to better understand the dynamical origin of the small satellites. We found that the four small moons are long-term stable and no mark of chaos is found for them. Aegaeon, Methone and Anthe could remain unaltered for at least 0.5 Myr, given the current configuration of the system. They remain well trapped in the corotation eccentricity resonances with Mimas in which they currently librate. However, perturbations from nearby resonances, such as Lindblad eccentricity resonances with Mimas, seem responsible for largest variations observed for Methone and Anthe. Pallene remains in a non-resonant orbit and it is the more stable, at least for 64 Myr. Nonetheless, it is affected by a quasi-resonance with Mimas, which induces long-term orbital oscillations of its eccentricity and inclination.

 

 

 

Ponente: 

 

Carlos del Burgo (INAOE)

 

Fecha:

 

Miércoles 15 de Noviembre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

Testing stellar evolutionary models from detached eclipsing binary stars

 

Resumen:

 

We employ a Bayesian method to infer stellar parameters from the PARSEC v1.2S library of stellar evolution models and test the accuracy of these theoretical predictions. Detached eclipsing binaries are ideal for the performance of the tests. We employ a compilation of 165 detached eclipsing binary systems of our galaxy and the Magellanic clouds with reliable metallicities and measurements for the mass and radius to 2 per cent precision for most of them. We complement the analysis with 107 stars that are closer than 300 pc, for which we adopted solar metallicity. The applied Bayesian analysis relies on a prior for the initial mass function and flat priors for age and metallicity, and it takes on input the effective temperature, radius, and metallicity, and their uncertainties, returning theoretical predictions for other stellar parameters of the binaries. Our research is mainly based on the comparison of dynamical masses with the theoretical predictions for the selected binary systems. We determine the precision of the models. Also, we derive distances for the binaries, which are compared with trigonometric parallaxes whenever possible. We discuss the effects of evolution and the challenges associated with the determination of theoretical stellar ages.

 

 

Ponente: 

 

Mamadou N’Diaye  (Observatoire de la Côte d’Azur, Nice, France)

 

Fecha:

 

Martes 21 de Noviembre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

Imaging Earth-like planets with future observatories

 

Resumen:

 

Searching for habitable worlds with direct imaging and spectroscopy requires a telescope large enough to provide angular resolution and high sensitivity to planets around a significant number of nearby stars. Segmented aperture telescopes represent a compelling option but their geometry makes high-contrast imaging extremely challenging. In this presentation, I will review the challenges in wavefront control and starlight suppression to achieve contrast levels (flux ratio between star and planets) up to 10^10 at separations smaller than 100 mas. I will introduce ZELDA and ZAP, two concepts based on interferometric methods to measure differential aberrations in coronagraphic instruments. I will then show the results of our concept validation with prototypes on the exoplanet imagers VLT/SPHERE and Subaru/SCExAO, allowing the possible observation of cold self-luminous planets with these instruments. I will finally present our recent solutions for starlight suppression with novel coronagraph designs that are compatible with segmented aperture telescopes to detect and study rocky planets around nearby stars with future observatories (E-ELT, LUVOIR/HabEx missions).

 

 

Ponente: 

 

Eliab Felipe Canul Canché (IA-UNAM)

 

Fecha:

 

Miércoles 22 de Noviembre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

La Reunión de Estudiantes de Astronomía: historia, objetivos y expectativas futuras

 

Resumen:

 

La Reunión de Estudiantes de Astronomía (REA) es una reunión nacional anual organizada por estudiantes que tiene como propósitos principales:

  • · Vincular profesionalmente a los estudiantes de las diversas instituciones y programas de posgrado en astronomía y astrofísica del país.
  • · Dar un espacio a los estudiantes para presentar y defender sus trabajos científicos promoviendo el intercambio de ideas y colaboraciones futuras.
  • · Fomentar el interés en la astronomía en los estudiantes de licenciatura e ingeniería como una opción sólida de posgrado.

Desde hace 6 años, la REA ha fungido como un punto de encuentro en el que los estudiantes comparten su conocimiento en un área de la astronomía, en un ambiente incluyente y de confianza para todos los participantes.

En esta charla hablaremos de las motivaciones que se tuvieron para crear la REA, la historia y el impacto que la misma ha tenido a lo largo de los últimos 6 años, los objetivos logrados en la última reunión y las expectativas que se tienen para la REA en el futuro.

 

 

Ponente: 

 

Dr. Eduardo Reinoso Angulo (Instituto de Ingeniería UNAM)  

 

Fecha:

 

Miércoles 29 de Noviembre del 2017

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

Algunas lecciones de los sismos de septiembre del 2017

 

Resumen:

 

Se presentarán las principales características de los sismos de septiembre: 

sismicidad, intensidad sísmica y daños. Se pondrá especial énfasis en las fallas 

estructurales que causaron colapsos y víctimas, así como una comparación de 

las intensidades registradas por la instrumentación de la UNAM y lo contenido 

en el reglamento de construcciones 

 

 

 

Ponente: 

Jorge Barrera-Ballesteros (U. John Hopkins)

 

Fecha

Miércoles 13 de Diciembre del 2017

 

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

 Chemical Evolution in the Era of IFU surveys: The SDSS-IV MaNGA view.

 

Resumen:

 

 I will present the main results of our analysis of the local
metallicity of the ionized gas for more than 9×10^5 star
forming regions (spaxels) located in 1023 nearby galaxies
included in the SDSS-IV MaNGA IFU survey. Among them, I will
show the local mass - metallicity relation; its weak
relation with global parameters as well as the lack of
secondary relation of the global MZR with the SFR. We also
explore the impact of the gas fraction in the local
enrichment of MaNGA galaxies and comparisons with simple
chemical evolutionary models. At kpc scales, the observed
metallicity can be explained as a local version of the
well-known gas regulated chemical model with outflows driven
by stellar winds and SN explosions.

 

 

 

Ponente: 

Sebastian Sanchez (IA-UNAM)

 

Fecha

Miércoles 17 de Enero del 2018

 

 

Hora y Lugar:

12:00h, Sede IA-CU

Auditorio Paris Pishmish 

 

Titulo: 

 

 Reunion con los tutores de postgrado.

 

Resumen:

 

 En esta reunion se tocarán los siguientes temas:


1) La necesidad de aumentar el grupo de personas que se ofertan para dar los cursos, tanto propedeuticos, com
de materias básica (y temas selectos). En muchas ocasiones el CA no tiene margen de decisión sobre las personas
a dar los cursos incluso en aquellos casos que tenemos retroalimentación de los alumnos que los mismos han presentado
algun tipo de problemas. Es necesario que aquellas personas que no den cursos, o no tengan estudiantes a su cargo
traten de realizar un esfuerzo para ofertarse para dichos cursos de forma que el CA pueda seleccionar a los mejores
candidatos o al menos tengo alguna forma de rotación de profesores.

2) La necesidad de entender adecuadamente las normas que rigen nuestro postgrado y que la documentación, requisitos,
y procesos asociados con el mismo se hagan de la forma más adecuada posible. En muchos casos vemos estudiantes
que no presentan de forma adecuada los proyectos de tesis, o las candidaturas, o que no acaban de comprender las
fases que se requiere para la conclusion de la maestria o del doctorado. Igualmente en muchos casos las funciones
de los Comités Tutoriales no están claras para los alumnos o no
hacen uso de esta herramienta que está para ayudarles.

Esta problematica afecta a todo el instituto, pero principalmente el problema está en la sede de CU. Aun asi, trataremos
de conectarnos por videoconferencia para que la sede de Ensenada también pueda participar y quizás nos aporte una visión
diferente. Por supuesto la participación del resto de los miembros del Comité Académico que puedan participar es más
que bienvenida.

Finalmente quisiera escuchar su opinion o sus ideas sobre el funcionamiento del postgrado y si alguien ha tenido algun problema
concreto o quiere presentar alguna idea querría que lo hablásemos.

 

 

 

Ponente: 

Marc Lachieze-Rey (APC-Paris)

 

Fecha

Miércoles 24 de Enero del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

The roads to quantum gravity

 

Resumen:

 

There are conceptual arguments in favor of the quantization of gravity. In astrophysics, there are also some claims that  this could help to solve the dark matter and dark energy problems, as well as giving insights to the physics of black holes and the Planck era. I will present some of the tracks which are presently explored for this task, with special 

emphasis on loop quantum gravity.

 

 

 

 

Ponente: 

Sergio Hojman  (Universidad Adolfo Ibáñez, Chile)

 

Fecha

Miércoles 31 de Enero del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

Birrefringencia y dispersión de la luz en campos gravitacionales

 

Resumen:

 

Se muestra que hay soluciones de las ecuaciones de Maxwell en fondos gravitacionales de interés físico en las que la transmisión de ondas electromagnáticas es dispersiva y depende tanto de su polarización como de su dirección de propagación. Se comenta acerca de las implicaciones teóricas y posibles corroboraciones observacionales.

 

 

 

Ponente: 

Hector Ibarra  (IA-CU)

 

Fecha

Miércoles 14 de Febrero del 2018

 

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

The fossil record method to reconstruct the evolution of galaxies

 

Resumen:

 

We want to explore what are the advantages and limitations of the fossil record method and show some results of the application of this technique using the MaNGA data. In the first part of this talk, we have post-processed two Milky Way-sized zoom-in Hydro simulations to create a set of mock observations to test the robustness of the fossil record inferences. In the second part, we explore the resolved star formation histories of 140 AGNs, 1,079 star-forming galaxies, 593 green valley galaxies and 961 quenched galaxies with the aim to reconstruct their evolutionary tracks along the main sequence diagram.

 

 

 

Ponente: 

Eréndira M Huerta  (OAR-INAF)

 

Fecha

Miércoles 28 de Febrero del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

Highly Ionized X-ray Absorbers in AGNs and their Energetic: the case of NGC 4051

 

Resumen:

 

Highly ionized absorbers are ubiquitously found in the nuclear environment of the Active Galactic Nuclei (AGN's), in ~ 50% of type 1 Seyferts and QSOs. Their absorption lines are always detected blue-shifted compared to the host galaxy reference system, which implies that the ionized material is being ejected from the nucleus and driven outwards. The AGN's ionized outflows are often invoked as one of the key-players in the AGN-Host Galaxy-Circum Galactic medium Feedback process. In this talk I will talk of the particularly fortunate case of NGC 4051 which presents at least two different highly ionized outflows detected in the soft X-ray band from XMM-Newton space telescope observations.

 

 

 

Ponente: 

Karo Michaelian (IF-UNAM)

 

Fecha

Miércoles 08 de Marzo del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

Spectral Constraints on Life Giving Stars

 

Resumen:

 

Ultraviolet light in the UV-C region of the spectrum incident on primordial gases such as N2, CO2, CH4, and H2O can initiate its spontaneous dissipative structuring into chromophores which can then catalyze their own replication. Examples of such chromophores are the nucleic acids. This production, proliferation, and even the evolution towards ever more complex dissipative coupling of UV-C chromophores, similar to the historical ecological process observed on Earth, requires the continuous dissipation of a particular UV-C photon potential. This imposes constraints on the stellar light environment at the surface of planets similar to our own which could harbor life similar to our own. Habitable zones devoid of a continuous flux of UV-C light are untenable. This analysis could aid astrobiologists in targeting stellar systems most appropriate for the search of Earth-like biosignatures.

 

 

 

 

Ponente: 

Hector Ibarra  (IA-CU)

 

Fecha

Miércoles 04 de Abril del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

VLTI - GRAVITY chromatic imaging of Eta Car's core

 

Resumen:

 

Eta Car is one of the most massive, and intriguing, Luminous Blue Variables known. In its core resides a binary with a 5.54 years orbital period. Visible, infrared, and X-ray observations suggest that the primary star exhibits a very dense wind with a terminal velocity of about 400 km/s, while the secondary shows a much faster and less dense wind with a terminal velocity of 3000 km/s. The wind-wind collision zone at the core of Eta Car is thus a complex region that deserves a detailed study to understand the effect of the binary interaction in the evolution of the system. In this talk we will perform a review of the basic principles of the optical/near-infrared interferometry, together with our unique imaging campaign with VLTI - GRAVITY of the Eta Car's core. The superb quality of our interferometric data, together with state-of-the-art image reconstruction techniques, allowed us to obtain, with milliarcsecond resolution, continuum and chromatic images across the BrG and HeI lines in the Eta Car K-band spectrum (R~4000). These new data together with models of the primary wind of Eta Car has letting us to characterize the spatial distribution of the dust and gas in the inner 40 AU wind-wind collision zone of the target.

 

 

 

 

Ponente: 

Alain Klotz (IRAP)

 

Fecha

Martes 10 de Abril del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Antiguo

 

Titulo:  

Twenty Years of Observations with TAROT

 

Resumen:

For twenty years a network of small aperture, large field of view,
optical telescopes is used to record the first hours after gamma
ray burst (GRB) events. Outside the GRB time, the telescopes are 
used for routine observation programs from solar system bodies
to quasars. This talk will present how such a small telescopes can
provide science in various astrophysical topics. As the Instituto
Astronomia is installing small telescopes at OAN-SPM (DDOTI,
COATLI) the TAROT experience can bring some ideas concerning
observation topics and techniques.

 

 

 

 

Ponentes: 

1) Reporte de JOAN Mauricio Reyes. (15min+5) 
2) Reporte de Secretario Técnico OAN SPM Manuel Núñez (15 min+5) 
3) Reporte de Jose Peña (Secretario Técnico OAN TNT) (15min+5) 
4) Reporte de Sergey Zharikov (JDAO, CATT) (15min+5). 
5) Preguntas, discusión general  ~40 min.

 

Fecha

Miércoles 11 de Abril del 2018

 

 

Hora y Lugar: 

13:30h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  

Reunion de usuarios del OAN. 

 

Resumen:

Ya paso bastante tiempo después de la última reunión de los usuarios del OAN.
Es tiempo para dar un informe a la comunidad de los usuarios del OAN sobre nuestro estado actual y futuros planes.

 

 

 

Ponentes: 

Alejandro Aguayo-Ortiz, Sergio Mendoza, y Daniel Olvera (IAUNAM)

 

Fecha

Miércoles 18 de Abril del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  Aztekas: A GNU Public Licensed numerical code for solving conservative

equations using a direct Primitive Variable Recovery Scheme (PVRS):
applications to relativistic hydrodynamics.

 

Resumen:

 

In this talk we will discuss a Primitive Variable Recovery Scheme (PVRS)
to solve any system of coupled differential conservative equations. This
method obtains directly the primitive variables applying the chain rule
to the time term of the conservative equations. With this, a traditional
finite volume method for the flux is applied in order avoid violation
of both, the entropy and "Rankine-Hugoniot" jump conditions. The time
evolution is then computed using a forward finite difference scheme. This
numerical technique evades the recovery of the primitive vector by
solving an algebraic system of equations as it is often used and so, it
generalises standard techniques to solve these kind of coupled systems.
Applications to special relativistic hydrodynamics including in some
cases a fixed background curved space-time will be discussed.  We will
also talk about the development of aztekas.org a free GPL'd code for
solving any set of coupled conservative equations.

 

 

 

 

 

Ponentes: 

Diego López Cámara (IAUNAM)

 

Fecha

Miércoles 25 de Abril del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  Aunque el GRB asociado al GW170817 es totalmente atípico, éste puede ser modelado por la emisión de un GRB-corto “estratificado” visto fuera de eje.

 

Resumen:

 

El 17 de agosto del 2017 es un día épico y un parteaguas. En dicha fecha se detectó por primera vez tanto ondas gravitacionales, así como la radiación electromagnética de un mismo objeto o fenómeno. Mientras LIGO-Virgo detectó la primera señal de ondas gravitacionales producidas por la fusión de dos estrellas de neutrones (GW170817), los satélites Fermi e Integral detectaron emisión electromagnética (EM) de corta duración proveniente de exactamente la misma región del cielo. Dicha emisión EM (gamma y X), resulta ser totalmente atípica al de los GRBs-cortos, y hasta se ha llegado a especular que ni siquiera es un GRB corto si no un nuevo tipo de fenómeno transitorio de alta energía. 

 

Así, en mi charla primero explicaré las características de GW170817, así como las de su contraparte EM que han sido observada por más de 160 días. Luego, discutiré los modelos principales para explicar el flujo (en X, óptico, y el radio) observado. Finalmente, mostraré como los flujos observados pueden ser explicado mediante el modelo clásico de los GRBs cortos bajo ciertas condiciones: tener un jet relativista colimado que no es atenuado por su cocoon correspondiente (modelo conocido como “jet exitoso” o “jet estratificado”), moviéndose a través del medio interestelar y observado desde unos 30 grados fuera de eje del movimiento de jet-cocoon.

 

 

 

 

 

Ponente: Magda Gonzalez (IAUNAM)

 

Fecha

 Miércoles 02 de Mayo del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  Sobre las observaciones de Geminga con HAWC y algo más

 

Resumen: El pasado marzo 2018 el observatorio HAWC cumplió 3 años de operación continúa con sus 300 detectores de Cherenkov. En estos tres años se han anunciado resultados muy interesantes con las observaciones de HAWC como su primer mapa de fuentes emisoras de gammas a energías de TeV, el seguimiento de la onda gravitacional GW170817 y fuertes evidencias que apuntan a que el principal candidato a explicar el exceso de positrones que observan los satélites AMS y Pamela NO es el pulsar Geminga como se esperaba. En mi charla, presentaré los resultados más interesantes de HAWC en estos 3 años y los que están por publicarse.

 

 

Ponente: Dr. Mauricio García (IBM)

 

Fecha

Viernes 04 de Mayo del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  Introducción al cómputo cuántico y la plataforma IBM Q

 

Resumen:

En esta sesión se explorarán los principios del cómputo cuántico y sus aplicaciones. Se profundizará en las diferencias fundamentales con el cómputo clásico, y se presentará la plataforma IBM Q como ejemplo de implementación de este paradigma.

 

 

 

Ponente: Aida Kirichenko (IAUNAM)

 

Fecha

Miércoles 09 de Mayo del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo:  Optical/near-IR studies of pulsars and pulsar binary systems

 

Resumen: The talk is dedicated to optical/nIR observations of two isolated pulsars and a pulsar in a binary system with the GTC and the VLT. In case of the isolated pulsars, we report detection of both objects and discuss constraints on their multiwavelength spectra. For the binary system, we present detection of the pulsar binary companion and discuss implications following from the optical observations and the radio timing analysis.  

 

 

 

Ponente: Quentin Salome (IRyA)

 

Fecha

Miércoles 23 de Mayo del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo: AGN feedback and jet-induced star formation in nearby radio galaxies

 

Resumen: Star formation is one of the key mechanisms driving the evolution of galaxies across cosmic times. The physical properties and dynamics of the molecular gas influence the star formation efficiency. Looking at large scales is therefore essential to understand the multi-scale physics of star formation. The environment may play a role in star formation. In particular, recent studies suggest that AGN can regulating/quenching star formation in galaxies (negative feedback). However, evidence of AGN positive feedback, that enhances star formation, is also invoked in a few radio galaxies, in particular in regions of radio jet-gas interaction (eg. Centaurus A, Minkowski's Object).


I will present different studies of the northern filaments of Centaurus A at different resolutions. These filaments extend on scales up to 6 kpc, aligned with the radio-jet, and show evidence of recent star formation (Rejkuba et al. 2001). Along the radio jet, at the intersection of the radio jet and a HI shell (Schiminovich et al. 1994), CO emission has been detected with SEST in the shell (Charmandaris et al. 2000). We detected CO in a much larger area along the filaments with APEX, including outside the HI gas (Salomé Q et al. 2016). Recently, we obtained ALMA observations along the filaments, at a resolution of ~20 pc (Salomé Q. et al. 2017). Such resolution enables to separate giant molecular without resolving them.

 

 

 

 

 

Ponente: Javier Garcia Vazquez (IPN-ESFM)

 

Fecha

Miércoles 13 de Junio del 2018

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo: Turbulencia en regiones HII extragalácticas

 

Resumen: Se presenta un estudio estadístico de una región HII extragaláctica  en diferentes líneas de emisión. Consideramos al medio interestelar en un estado turbulento desde el punto de vista de la dinámica de los fluidos. Interesa determinar de qué manera  fenómenos físicos suministran energía al medio interestelar y las consecuencias de las interacciones dentro de la región HII. La investigación presenta los resultados obtenidos de un análisis estadístico de dos puntos del campo de velocidades basados en la función de autocorrelación (R) y la función de estructura (S). Por medio de este análisis es posible obtener el espectro de energía y así comparar las observaciones con teorías establecidas. Se muestran las ventajas y desventajas de estos métodos, así como el alcance que proveen desde el enfoque astrofísico.

 

 

 

Ponente: Joel Sánchez (ESO-Chile)

 

Fecha

Jueves 14 de Junio del 2018

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo: Science with Optical/Infrared interferometry: from Sparse Aperture Masking to the VLTI

 

 

Resumen:  In this talk we will perform a review of the basic principles of the optical/near-infrared interferometry and of the current European facilities to use this observational technique. Particularly, we will describe the interferometric observables used at near-infrared wavelengths. We will provide a review of the current (and future) instruments available at the ESO Very Large Telescope Interferometer (VLTI), their advantages and limitations as well as, the typical science cases to be addressed with them.  Finally, we will provide a general frame of the current software available for VLTI data analysis.

 

 

Ponente: Jordi Casanova Bustamante (Oak Ridge National Laboratory, USA)

 

Fecha

Miércoles 05 de Septiembre del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo: Multi-dimensional Simulations of Mixing in Classical Novae

 

Resumen: Classical novae are explosive phenomena that take place in stellar binary systems. They are powered by mass transfer from a low-mass, main sequence star onto a white dwarf. The material piles up under degenerate conditions until a thermonuclear runaway ensues. The energy released by the suite of nuclear processes operating at the envelope heats the material up to peak temperatures about (0.1-0.4) GK. During these events, material enriched in CNO and other intermediate-mass elements, are ejected into the interstellar medium. To account for the gross observational properties of classical novae (in particular, a metallicity enhancement in the ejecta above solar values), 1D models often assume mixing between the (solar-like) material transferred from the companion and the outermost layers (CO- or ONe-rich) of the underlying white dwarf. The origin of the large enhancements and inhomogeneous distribution of chemical species observed in high-resolution spectra of ejected nova shells has, however, remained unexplained for almost half a century. I will present multi-D simulations of classical novae with the FLASH code, and will discuss the role of Kelvin-Helmholtz instabilities as a natural mechanism for self-enrichment of the accreted envelope with core material. Such mixing also naturally produces large-scale chemical inhomogeneities. Both the metallicity enhancement and the intrinsic dispersions in the abundances are consistent with the observed values. 

 

 

Ponente: Mary Loli Martínez-Aldama (IAA, España)

 

Fecha

Jueves 06 de Septiembre del 2018

 

 

Hora y Lugar: 

12:00h, Sede IA-CU,

 Auditorio Paris Pishmish

 

Titulo: Extreme quasars at high redshift

 

Resumen: The study of the AGN accreting close to the Eddington limit (L/LEdd~1) has taken an important role, due to their potential use as standard candles for cosmological applications.  With the purpose to understand the physics of extreme quasar, we perform a spectroscopic analysis of a sample of highly accreting quasars at high redshift (z~2–3). Our sample were observed with the OSIRIS spectrograph on the GTC 10.4 m telescope located at the Observatorio del Roque de los Muchachos in La Palma. The highly accreting quasars were identified using the 4D Eigenvector 1 formalism, which is able to organize type 1 quasars over a broad range of redshift and luminosity. The kinematic and physical properties of the broad line region have been derived by fitting the profiles of strong UV emission lines such as AlIII λ1860, SiIII]λ1892 and CIII]λ1909.  We find  that AlIIIλ1860 can be associated with a low-ionization virialized sub-system. xA sources show strong blueshifts in the high-ionization lines like in CIVλ1549, indicating a relation between the high Eddington ratios and the productions of outflows.  The extreme radiative properties of highly accreting quasar make them prime candidates for maximum feedback effects on the host galaxy. The characterization of extreme quasar allow to assemble large samples of extreme quasars from the latest data releases of the SDSS, especially useful for deriving independent estimates of ΩM in the redshift range 1<z<3.5.

 

 

 

 

 

 

 

 


  

 


 

 
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