RMxAA: Abstracts of Accepted Papers for Volume 54 Number 2


March 8, 2018

2018: March April May June July



March 2018


ON THE IMPACT OF CENTRAL OBSCURATION ON THE EFFECTIVENESS OF GROUND-BASED O/IR TELESCOPES

A. V. Hakobyan1

1Byurakan Astrophysical Observatory, Armenia.


armhakobyan@bao.sci.am

Received: December 6 2017
Accepted: March 8 2018

Abstract: Annular apertures are typical in modern reflective telescopes. They exhibit altered shapes of PSF and OTF if compared with perfect circular one. As a consequence the optical power of such a telescope is also changing. This can be calculated with the use of classical optics theory. But presence of atmospheric optical turbulence contributes its own effects. In this work trend of the main performance characteristics through broad spectral region (300 - 5000~nm) for different obscuration and atmospheric conditions is considered. It turned out that in certain conditions performance (angular resolution, integral contrast and signal-to-noise ratio) of an obstructed telescope relative to a circular aperture case can be even worst than in the absence of turbulence. In particular, relative imaging performance of an 8m telescope with high (ϵ = 0.6) central obscuration as a typical example of modern large size survey telescope is analyzed.



OPTICAL POLARIZATION STUDY ON THE REGION CENTAURUS: NGC 5662

M. M. Vergne1,2, Carlos Feinstein1,2, and Ruben E. Martínez2,†

1Facultad de Ciencias Astronómicas y Geofísicas, Observatorio Astronómico, La Plata, Argentina.
2Instituto de Astrofísica de La Plata (UNLP - CONICET), Facultad de Ciencias Astronómicas y Geofísicas, La Plata, Argentina.
In memoriam.


carlosfb@gmail.com

Received: December 23 2017
Accepted: March 13 2018

Abstract: We present (BVRI) multicolor linear polarimetric data of 73 of the brightest stars in the open cluster NGC~5662. Our objective is study the characteristics of the interstellar medium (ISM) towards and in the environment of it. NGC~5662 is polarimetrically characterized by $ P_{V}$ = 2.27$\% \pm 0.13 $ and $\theta_{V}$=89$^0$.6 $\pm$ 1.17. Its Polarization Efficiency is much higher than the normal efficiency of ISM. The observed visual polarization in NGC~5662 is caused at least by three components of dust at $\sim$ 200 pc, 500 pc and 900 pc from the Sun.These have different polarimetric characteristics and the layer located at 500 pc has variable density. The absorption presents a different behavior to the polarization as the distance increase. A few of the observed stars present evidences of intrinsic polarization.



ESTIMATION OF THE STAR FORMATION RATE USING LONG-GAMMA RAY BURST OBSERVED BY SWIFT

M. Elías1 and M. Martínez1

1Benemérita Universidad Autónoma de Puebla, Puebla, Puebla, México.


Mau 584@hotmail.com

Received: November 29 2017
Accepted: March 13 2018

Abstract: In this work we estimate the Star Formation Rate (SFR) through 333 Long-GRBs detected by Swift. This investigation is based on the empirical model proposed by \citet{Yuksel2008}, basically, the SFR is estimated using long-GRBs considering that they have an stellar origin based on the Collapsar model or the collapse of massive stars (Hypernova) $M>20 M_{\bigodot} $. The analysis starts with the study of $\varepsilon (z)$ which accounts the long-GRBs production rate and it is parameterized by $\varepsilon(z)=\varepsilon_{0}(1+z)^{\delta} $ where $\varepsilon_{0}$ include the SFR absolute conversion to GRBs rate in a luminosity range already defined and $\delta$ is a dynamical parameter which changes at different regions of redshift it accounts the SFR slope which is obtained by an analysis of linear regression over our Long-GRBs sample, the results obtained provide evidence that support our proposal to use Long-GRBs as tracers of SFR.



NUMERICAL SIMULATION OF THE HH 30 ASTROPHYSICAL JET NEAR ITS LAUNCH SITE

Carl L. Gardner1, Jeremiah R. Jones1, and Perry B. Vargas1

1School of Mathematical & Statistical Sciences, Arizona State University, Tempe, AZ, USA.


carl.gardner@asu.edu

Received: December 13 2017
Accepted: March 28 2018

Abstract: We simulate the surface brightness of the HH 30 astrophysical jet near its launch site in the forbidden [O I], [N II], and [S II] doublets by post-processing gas dynamical simulations of densities and temperatures, using spectral line emission data from the astrophysical spectral synthesis package {\em Cloudy}. We then compare the simulated surface brightness in each line with {\em Hubble Space Telescope}/observations of Hartigan and Morse and with multiple-ion magnetohydrodynamic simulations of Tesileanu et al. The general trend of our simulated surface brightness in each doublet using the gas dynamical {\em Cloudy} approach is in excellent agreement with the observational data, verifying our choices of initial jet and ambient densities and jet temperature, as well as the number and sequencing of the jet pulses over the 35 year evolution of the jet near its launch site.




April 2018


VARIABLE STARS IN NGC 4147 REVISITED: RR LYRAE STARS NEW CCD \emph{VI} PHOTHOMETRY AND PHYSICAL PARAMETERS

A. Arellano Ferro1, F. C. Rojas Galindo2, S. Muneer3, and Sunetra Giridhar3

1Instituto de Astronomía, Universidad Nacional Autónoma de México, México.
2Instituto de Física, Universidad de Antioquia, Colombia.
3Indian Institute of Astrophysics, Bangalore, India.


armando@astro.unam.mx

Received: January 30 2018
Accepted: April 9 2018

Abstract: We have calculated the physical parameters of the RR Lyrae stars in the globular cluster NGC 4147 via the Fourier decomposition of their light curves, using new data and well-established semi-empirical calibrations and zero points. The mean metallicity and distance estimated using the RRc stars are [Fe/H]$_{ZW}=-1.72\pm0.15$ and $19.05\pm 0.46$ kpc, respectively. The star V18, whose variability has been previously in dispute, is confirmed to be a variable of the SR type with a period of about 24.8d, and it has been used to get an independent distance estimate of the cluster. It is observed that the RRab and RRc stars do not share the inter-mode region in the horizontal branch. The cluster can be classified as of intermediate Oosterhoff type. Its horizontal branch structure and metallicity make a good case for extragalactic origin. It follows the distribution of Oo I type globular clusters in the $M_V-$[Fe/H] plane, as depicted from the RRc stars.




May 2018


AGB CANDIDATES IN THE FIELD OF $\gamma$ CAS1

R. Nesci2, T. Tuvikene3, C. Rossi4, S. Gaudenzi2, S. Galleti5, P. Ochner6,7, and H. Enke8

1Based on observations collected with the Cassini Telescope at Loiano station of the INAF-Bologna Astronomical Observatory, the 67/90 Schmidt telescope and the Copernico Telescope of the INAF-Padova Astronomical Observatory, the 122-cm telescope of the Padova University.
2INAF/IAPS, Roma, Italy.
3Tartu Observatory, University of Tartu, Estonia.
4INAF/ Osservatorio di Monte Porzio, Roma, Italy.
5INAF-IASF, Bologna, Italy.
6INAF-Osservatorio Astrofisico Asiago, Italy.
7Dipartimento di Fisica e Astronomia, Universita' di Padova, Italy.
8Leibniz-Institut für Astrophysik, Potsdam (AIP), Germany.


roberto.nesci@iaps.inaf.it

Received: February 14 2018
Accepted: May 23 2018

Abstract: We report the spectroscopic and photometric monitoring of a sample of 530 candidate AGB stars in a $5\times 5$ degrees field, selected from the IPHAS catalog; historic light curves were derived from Asiago IR plates taken in the years 1965 -1984. We found 10 Miras, 5 stars with long term trends, 3 semiregular and 3 irregular. Spectral types from CCD slit spectra gave 8 M-type, 7 C-type and 6 S-type stars. In the color-color plots made from IPHAS and 2MASS catalogs, the S-type and M-type stars occupy the same regions, while C-type stars are well separated. All C-type stars with IR excess show long term trends in their light curve. Distances of the Mira stars, estimated from their periods and K magnitudes, give a median value 4.9 kpc with a large spread. A comparison with astrometric parallaxes from Gaia DR2 is briefly discussed.




June 2018


$\delta$ Mus REVISITED4: RECTIFYING A 82 yr-OLD MISTAKE

Dimitri Pourbaix1,2 and Henri M. J. Boffin3

1Institut d'Astronomie et d'Astrophysique, Universit\'e Libre de Bruxelles, Belgium.
2F.R.S.-FNRS, Belgium.
3ESO, Germany.
4Based on data obtained from the ESO Science Archive Facility under request numbers Pourbaix/336063.


pourbaix@astro.ulb.ac.be

Received: April 27 2018
Accepted: June 4 2018

Abstract: The red giant $\delta$ Muscae is known since 1919 to be a spectroscopic binary, and the first and only orbit was determined in 1936, claiming the period to be 847 days. This was discrepant with the Hipparcos determined astrometric orbit. Using the latest data available for this object - leading to a 100 yr time-span - we show here that the correct period is 423 d, and are able for the first time to combine the spectroscopic orbit with the Hipparcos orbit. Using all the available information, we find that the $\sim$1.2 \Msun red giant must have a $\sim 0.3-0.4$ \Msun M dwarf companion, and that the system will soon evolve towards a He WD binary system. Given its relatively short period, $\delta$ Muscae may be an ideal benchmark for testing astrometric orbits obtained by Gaia for very bright stars.



EXACT TRAVELING WAVE SOLUTIONS OF KDV EQUATION FOR DAWS IN SUPERTHERMAL PLASMA

U. M. Abdelsalam1 and M. S. Zobaer2

1Department of Mathematics, Faculty of Science, Fayoum University, Fayoum, Egypt.
2Department of Physics, Bangladesh University of Textiles, Dhaka 1208, Bangladesh.


usama.ahmad@rub.de

Received: January 29 2018
Accepted: June 5 2018

Abstract: A propagation of fully nonlinear dust-acoustic waves (DAWs) in superthermal plasma is investigated. The plasma is described by the hydrodynamic dust fluid equations with superthermal electrons and ions, where both follow kappa distribution. The reductive perturbation method is used to analyze small but finite amplitudes nonlinear DAWs. Extended homogeneous balance method is applied to obtain the exact traveling wave solutions for the Korteweg-de Vries (KdV) equation. The solutions are numerically analyzed to study the characteristics of arbitrary and small but finite amplitudes DAWs. This study is important for understanding the nonlinear excitations that may appear in astrophysical plasma objects such as in Jupiter magnetosphere.



KINEMATICS OF THE GALACTIC BUBBLE RCW 120

M. Sánchez-Cruces1, A. Castellanos-Ramírez2, M. Rosado3, A. Rodríguez-González2, and J. Reyes-Iturbide4

1Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, México.
2Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México.
3Instituto de Astronomía, Universidad Nacional Autónoma de México, México.
4División de Mecánica. Tecnológico de Estudios Superiores de Tianguistenco, Estado de México, México.


monica.sanchez.cruces@gmail.com

Received: September 13 2017
Accepted: June 5 2018

Abstract: We studied the kinematics of the Galactic bubble RCW 120 in the [SII]$\lambda\lambda$6717,6731 \AA lines. We measured a LSR radial velocity ranging from $\approx -74$ to $\approx -6$ km s$^{-1}$. We found evidence of expansion only in the northeast region of the nebula (from 20 to 30 km s$^{-1}$). We found a high electron density around 4000 cm$^{-3}$ in the south-west region and we also found two arches-like structures indicating a density gradient. We present 3D numerical simulations of RCW 120 using the bibliography {\sc Walicxe-3D} code in order to explore the optical shell dynamics and its morphology. Our numerical results predict an average numerical electron density of the ambient medium (in the southern region of the object) between 3000 to 5000 cm$^{-3}$ in agreement with our values obtained from observations. From our models, we do not expect X-ray emission coming from the external shell, due to the low expansion velocity.



ON THE ORBITAL PERIOD OF THE CATACLYSMIC VARIABLE V767 CYG

A. Avilés1, P. García2, C. Chávez1, and E. Pérez-Tijerina2

1Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, México.
2Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, México.


andres.avileslv@uanl.edu.mx

Received: February 9 2018
Accepted: June 15 2018

Abstract: We present a photometric and spectroscopic study that helps to constrain the orbital period of the system V767 Cyg for the first time. From the analysis of the $V$ filter light curve besides of that for the radial velocity curve for different Balmer series lines, we find a most likely orbital period of $0.165\pm 0.012$ days for the binary system. The data we present were obtained during two different observational campaigns.



DETERMINATION OF STELLAR ATMOSPHERIC PARAMETERS FOR A SAMPLE OF POST-AGB STARS

R. E. Molina1

1Laboratorio de Investigación en Física Aplicada y Computacional, Universidad Nacional Experimental del Táchira, Venezuela.


rmolina@unet.edu.ve

Received: January 16 2018
Accepted: June 18 2018

Abstract: We report for the first time the stellar atmospheric parameters for a a set of post-AGB stars classified by Suárez et al. (2006). The stellar spectra were obtained in the optical region, with low-resolution and have different spectral ranges. We select a sample of 70 objects with A-K spectral types and luminosities I and Ie. The large majority of these objects have been scarcely studiedand are located toward the galactic south pole region. We employ a set of empirical relationships that use pseudo-equivalent widths as spectral features to estimate the effective temperature, surface gravity and metallicity. The criteria chosen to select the absorption lines are similar to those employed by the MK classification system.



KIMYA, A CODE FOR SOLVING CHEMICAL REACTION NETWORKS IN ASTROPHYSICS

A. Castellanos-Ramírez1, A. Rodríguez-González1, P. R. Rivera-Ortíz1, A. C. Raga1, R. Navarro-González1, and A. Esquivel1

1Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México.


antonio.castellanos@nucleares.unam.mx

Received: March 7 2018
Accepted: June 26 2018

Abstract: {\sc kimya} is a new code for solving the system of differential equations describing the temporal behavior of a chemical network. This paper presents a simple and easy to implement numerical method and tests of its accuracy. {\sc kimya} was designed for incorporating a chemical network into multi-dimensional gasdynamical simulations. In order to test our code we compute three numerical simulations: a model of the chemical evolution of a dark cloud (which we compare with previous calculations), and a model of nitric oxide formation during a lightning discharge simulated with a laser pulse. The latter is done with both a single parcel calculation, as well as a fully hydrodynamical/chemical model, which we compare with results from a laboratory experiment.



A WINDSWEPT CLOUD CORE ADJACENT TO HH 2

A. C. Raga1, B. Reipurth2, and A. Noriega-Crespo3

1Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México.
2Institute for Astronomy, University of Hawaii, USA.
3Space Telescope Science Institute, Baltimore, MD, USA.


raga@nucleares.unam.mx

Received: February 9 2018
Accepted: June 28 2018

Abstract: We analyze an H$\alpha$ image of the HH 1/2 region of unprecedented depth. In this image, the outflows and other emission structures of this region are clearly seen. We focus on a description of the ``hill', which is an approximately circular feature directly to the SW of HH 2. Through an analysis of our H$\alpha$ image and IR images (obtained with the IRAC camera of the Spitzer telescope), we show that while the ``hill'' is consistent with previous interpretations of this object as a PDR (excited by the UV radiation of HH 2), it also shows features implying that the partially photodissociated molecular clump is embedded in an environment which is streaming from N to S. This motion might be the result of the expansion of the Orion nebula, or of an uncollimated, outwards directed flow from the central region of the HH 1/2 system.




July 2018


STUDYING MID-RANGE PLANAR ORBITS AROUND PHOBOS

M. P. O. Cavalca1, A. F. B. A. Prado1, J. K. S. Formiga2, V. M. Gomes3, and D. M. Sanchez1

1National Institute for Space Research - INPE, São José dos Campos, Brazil.
2São Paulo State University - UNESP/ICT, São Josée dos Campos, Brazil.
3São Paulo State University - UNESP/FEG, Guaratinguetã, Brazil.


antonio.prado@inpe.br

Received: April 30 2018
Accepted: July 17 2018

Abstract: The goal of the present paper is to search and study mid-range planar orbits for a spacecraft traveling near Phobos. The first step is to make a numerical search and classification of natural orbits based in the concept of ``Quasi Satellite Orbits'' (QSO). The effects of the eccentricity of Phobos and the irregular shape of the bodies involved (Mars and Phobos) are studied, identifying the importance of these terms. This study is made using two different initial locations for Phobos, the periapsis and apoapsis. The results show the existence of several solutions, mapping the minimum, maximum and averaged Phobos-spacecraft distances.



THE HI- AND H2-TO-STELLAR MASS CORRELATIONS OF LATE- AND EARLY-TYPE GALAXIES AND THEIR CONSISTENCY WITH THE OBSERVATIONAL MASS FUNCTIONS

A. R. Calette1, Vladimir Avila-Reese1, Aldo Rodríguez-Puebla1,2,3, Héctor Hernández-Toledo1, and Emmanouil Papastergis4,5

1Instituto de Astronomía, Universidad Nacional Autónoma de México, México.
2Department of Astronomy & Astrophysics, University of California at Santa Cruz, USA.
3Center for Astronomy and Astrophysics, Shanghai Jiao Tong University, China.
4Kapteyn Astronomical Institute, University of Groningen, The Netherlands.
5Credit Risk Modeling Department, Co\"{o}perative Rabobank U.A., The Netherlands.


acalette@astro.unam.mx

Received: March 16 2017
Accepted: July 19 2018

Abstract: We compile and homogenize local galaxy samples with available information on morphology, and stellar, H I and/or H2 masses. After taking into account non gas detections, we determine the H I- and H2-to-stellar mass relations and their $1\sigma$ scatter for late- and early-type galaxies. These relations are fitted to single or double power laws. Late-type galaxies are significantly gas richer than early-type ones, especially at high masses. The H2-to-H I mass ratios as a function of $M_{*}$ are discussed. We constrain the distribution functions of the H I- and H2-to-stellar mass ratios. We find that they can be described by a Schechter function for late types and a (broken) Schechter + uniform function for early types. Using the observed galaxy stellar mass function and the volume-complete late-to-early-type galaxy ratio as a function of $M_{*}$, these distributions are mapped into H I and H2 mass functions. The mass functions are consistent with those inferred from large surveys. The results presented here can be used to constrain models and simulations of galaxy evolution.



STUDYING DIRECT AND INDIRECT EFFECTS OF IMPULSES IN POWERED AERO-GRAVITY-ASSIST MANEUVERS AROUND VENUS

J. O. Murcia1, A. F. B. A. Prado2, and V. M. Gomes3

1Course of Engineering and Space Technology, Space Mechanics and Control, National Institute for Space Research, INPE, Brazil.
2General Coordinator of the Graduate School, National Institute for Space Research, INPE, Brazil.
3São Paulo State University, UNESP, School of Engineering, Brazil.


jhonathan.pineros@inpe.br

Received: April 10 2018
Accepted: July 23 2018

Abstract: The study of aero-gravity-assisted maneuvers around Venus is the focus of the present paper. These are maneuvers that combine the passage by the gravity field of the planet with an impulsive maneuver that is applied at the moment of the closest approach around Venus, and the modification of the trajectory is made by lift and drag. This option gives new possibilities for the maneuver, which can vary the angle of curvature, the energy and the inclination of the spacecraft. The paper also studies the direct and the indirect effects of the application of an impulsive maneuver. This is done by measuring the effects of each individual force present in the dynamics, by the integration of the accelerations coming from those forces.