Ref: ASTROimport-952

A Complete Census of Dusty Evolved Stars in Local Group Dwarf Galaxies with Spitzer: Description and First Results

Boyer, M. L. ; Barmby, P. ; Bonanos, A. Z. ; Gehrz, R. D. ; Gordon, K. D. ; Groenewegen, M. A. T. ; Lagadec, E. ; Lennon, D. J. ; Marengo, M. ; McQuinn, K. ; Meixner, M. ; Skillman, E. D. ; Sloan, G. C. ; van Loon, J. T. ; Zijlstra, A. A.

published in American Astronomical Society Meeting Abstracts #219, 219, pp. 244.16 (2012)

Abstract: Highly evolved stars (massive stars and intermediate-mass Asymptotic Giant Branch -or AGB- stars) can become heavily enshrouded in dust. This material is ejected into the interstellar medium (ISM), driving galactic chemical evolution. The dwarf galaxies of the Local Group (LG) are ideal laboratories for studying dusty evolved stars since their stellar populations are resolvable and they span a wide range in metallicity, luminosity, star formation history, ISM content, and interaction history. The dust-producing phase is brief, so it is rare in low-luminosity dwarf galaxies. We must therefore observe a large sample of dwarf galaxies in order to build a sufficient evolved star database. We have obtained time with the Spitzer Space Telescope to complete a uniform census of LG dwarf galaxies (d 2 Mpc) with IRAC designed to detect and characterize the circumstellar dust around evolved stars. The scientific potential of such observations is immense, since IRAC provides the color information required for identifying dusty stars that are obscured in optical and near-infrared surveys. Our immediate science goals are to (1) analyze dust content and mass loss in AGB stars, (2) generate intermediate-age star formation histories using AGB stars, (3) analyze the infrared properties of massive evolved stars, and (4) identify targets for JWST follow-up. Here, we describe the program and present some first results.

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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