Ref: ASTROimport-879

The Radial Distribution of Asymptotic Giant Branch Stars in Nearby Dwarf Galaxies

Mitchell, M. B. ; McQuinn, K. B. ; Boyer, M. L. ; Skillman, E. D. ; Gehrz, R. D. ; Sloan, G. ; McDonald, I. ; Groenewegen, M.

published in American Astronomical Society Meeting Abstracts, 225, pp. 342.20 (2015)

Abstract: Asymptotic giant branch (AGB) stars are evolved stars that can experience repeated episodes of mass loss and dust production. As such, they are drivers of galactic chemical enrichment and evolution. While AGB populations have been imaged in many nearby galaxies at optical wavelengths, optical imaging can miss up to 50% of this population due to extinction. Not only is a significant population of AGB stars unidentified in optical surveys, it also is unclear whether younger (and more massive) AGB stars are preferentially obscured. Thus, the distribution, radial profile, and, potentially, age gradient of this important class of stars is not well-constrained in galaxies. The DUST in Nearby Galaxies with Spitzer (DUSTiNGS) survey is a 3.6 and 4.5 µm IRAC imaging survey from the post-cryogen Spitzer mission designed to catalog the evolved stars in 50 nearby dwarf galaxies and identify the most luminous, variable AGB stars. The resulting catalog of the resolved stellar populations at infrared wavelengths provides the means to trace the spatial distribution of evolved stars in the host galaxies. In this study, we use the DUSTiNGS dataset to create radial stellar profiles in nine of the DUSTiNGS sample. We compare the radial distribution of the total evolved stellar populations to the distribution of both the intermediate aged AGB stars and the optically identified, older red giant branch (RGB) stars from Hubble Space Telescope archival images. Additionally, we derive elliptical parameters for seven of the systems from the infrared data and compare these to parameters previously derived from optical data.

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Royal Observatory of Belgium > Astronomy & Astrophysics
Science Articles > Non-refereed Articles

 Record created 2016-07-01, last modified 2016-07-06