Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC). II. Cool Evolved Stars - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles The Astronomical Journal Year : 2011

Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC). II. Cool Evolved Stars

Martha L. Boyer
  • Function : Author
Jacco Th. van Loon
  • Function : Author
Iain Mcdonald
  • Function : Author
Margaret Meixner
  • Function : Author
Dennis Zaritsky
Karl D. Gordon
  • Function : Author
F. Kemper
  • Function : Author
Brian Babler
  • Function : Author
Miwa Block
  • Function : Author
Steve Bracker
  • Function : Author
Charles W. Engelbracht
  • Function : Author
Joe Hora
  • Function : Author
Remy Indebetouw
  • Function : Author
Marilyn Meade
  • Function : Author
Karl Misselt
  • Function : Author
Thomas Robitaille
  • Function : Author
Marta Sewiło
  • Function : Author
Bernie Shiao
  • Function : Author
Barbara Whitney
  • Function : Author

Abstract

We investigate the infrared (IR) properties of cool, evolved stars in the Small Magellanic Cloud (SMC), including the red giant branch (RGB) stars and the dust-producing red supergiant (RSG) and asymptotic giant branch (AGB) stars using observations from the Spitzer Space Telescope Legacy program entitled "Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity SMC," or SAGE-SMC. The survey includes, for the first time, full spatial coverage of the SMC bar, wing, and tail regions at IR wavelengths (3.6-160 μm). We identify evolved stars using a combination of near-IR and mid-IR photometry and point out a new feature in the mid-IR color-magnitude diagram that may be due to particularly dusty O-rich AGB stars. We find that the RSG and AGB stars each contribute ≈20% of the global SMC flux (extended + point-source) at 3.6 μm, which emphasizes the importance of both stellar types to the integrated flux of distant metal-poor galaxies. The equivalent SAGE survey of the higher-metallicity Large Magellanic Cloud (SAGE-LMC) allows us to explore the influence of metallicity on dust production. We find that the SMC RSG stars are less likely to produce a large amount of dust (as indicated by the [3.6] - [8] color). There is a higher fraction of carbon-rich stars in the SMC, and these stars appear to reach colors as red as their LMC counterparts, indicating that C-rich dust forms efficiently in both galaxies. A preliminary estimate of the dust production in AGB and RSG stars reveals that the extreme C-rich AGB stars dominate the dust input in both galaxies, and that the O-rich stars may play a larger role in the LMC than in the SMC.

Dates and versions

insu-03645892 , version 1 (19-04-2022)

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Martha L. Boyer, Sundar Srinivasan, Jacco Th. van Loon, Iain Mcdonald, Margaret Meixner, et al.. Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC). II. Cool Evolved Stars. The Astronomical Journal, 2011, 142, ⟨10.1088/0004-6256/142/4/103⟩. ⟨insu-03645892⟩
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