RevMexAA: Abstracts of Accepted Papers for Volume 49 Number 2

March 20, 2013

2013: March

March 2013

Diatomic Analytic Molecular Partition Functions for Stellar Atmospheres

O. Cardona and M. G. Corona-Galindo

Instituto Nacional de Astrofísica, Óptica y Electrónica, Tonantzintla, Puebla, Mexico

Received: 2012 December 10
Accepted: 2013 March 19

Abstract: Approximate partition functions and their derivatives for diatomic molecules are formulated taking into account the finite number of levels. A procedure is developed to derive compact analytic expressions, without free parameters, necessary for the efficient evaluation of some thermodynamic coefficient from the partition functions for diatomic molecules useful in modeling low temperature stellar atmospheres.

The VVV-SkZ_pipeline: an automatic PSF-fitting photometric pipeline for the VVV survey

Francesco Mauro,1 Christian Moni Bidin,1,2,5 André-Nicolas Chené,1,3 Doug Geisler,1 Javier Alonso-García,4 Jura Borissova,3,5 and Giovanni Carraro6,7

1Departamento de Astronomía, Universidad de Concepción, Chile
2Instituto de Astronomía, Universidad Católica del Norte, Antofagasta, Chile
3Departamento de de Física y Astronomía, Universidad de Valparaíso, Chile
4Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Santiago, Chile
5The Milky Way Millennium Nucleus, Santiago, Chile
6European Southern Observatory, Santiago, Chile
7Dipartimento di Fisica e Astronomia, Università di Padova, Padua, Italy

Received: 2012 November 14
Accepted: 2013 March 7

Abstract: We present the VVV-SkZ_pipeline, a DAOPHOT-based photometric pipeline, created to perform PSF-fitting photometry of "VISTA Variables in the Vía Láctea" (VVV) ESO Public Survey data. The pipeline replaces the user avoiding repetitive interaction in all the operations, retaining all of the benefits of the power and accuracy of the DAOPHOT suite. The pipeline provides an astrometrized photometric catalog reliable up to more than 2 magnitudes brighter than the saturation limit, where other techniques fail. It also produces deeper and more accurate photometry. These achievements allow the VVV-SkZ_pipeline to produce data well anchored to the selected standard photometric system and analyze important phenomena (i.e. TRGB, RGB slope, HB morphology, RR Lyrae), that other methods are not able to manage.

Environmental dependences of star formation rate (SFR), specific star formation rate (SSFR) and stellar mass at fixed luminosity

Xin-Fa Deng, Cheng-Hong Luo, Yong Xin, and Ping Wu

School of Science, Nanchang University, Jiangxi, China

Received: 2012 December 11
Accepted: 2013 March 7

Abstract: Using four volume-limited Main galaxy samples of the Sloan Digital Sky Survey Data Release 8 (SDSS DR8), we have investigated the environmental dependences of the SFR, SSFR and stellar mass at fixed luminosity. At fixed luminosity, we still observe strong environmental dependences of the SFR, SSFR and stellar mass of galaxies: galaxies in the lowest density regime preferentially have a higher SFR or SSFR and lower stellar mass than galaxies in the densest regime. This result suggests that the limitation or fixation of luminosity does not exert substantial influence on the environmental dependences of the SFR, SSFR and stellar mass of galaxies, which further shows that luminosity is not a fundamental parameter in correlations between galaxy properties and the environment.

Thermals in stratified regions of the ISM

A. Rodríguez-González and A. C. Raga

Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico

Received: 2012 September 19
Accepted: 2013 March 5

Abstract: We present a model of a "thermal" (i.e., a hot bubble) rising within an exponentially stratified region of the ISM. This model includes terms representing the ram pressure braking and the entrainment of environmental gas into the thermal. We then calibrate the free parameters associated with these two terms through a comparison with 3D numerical simulations of a rising bubble. Finally, we apply our "thermal" model to the case of a hot bubble produced by a SN within the stratified ISM of the Galactic disk.