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.
| Original language | English (US) |
|---|---|
| Article number | 103 |
| Journal | Astronomical Journal |
| Volume | 142 |
| Issue number | 4 |
| DOIs | |
| State | Published - Oct 2011 |
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Keywords
- circumstellar matter
- Magellanic Clouds
- stars: AGB and post-AGB
- stars: carbon
- stars: mass-loss
- supergiants
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Surveying the agents of galaxy evolution in the tidally stripped, low metallicity Small Magellanic Cloud (SAGE-SMC). II. Cool evolved stars. / Boyer, Martha L.; Srinivasan, Sundar; Van Loon, Jacco Th; McDonald, Iain; Meixner, Margaret; Zaritsky, Dennis F; Gordon, Karl D.; Kemper, F.; Babler, Brian; Block, Miwa; Bracker, Steve; Engelbracht, Charles W.; Hora, Joe; Indebetouw, Remy; Meade, Marilyn; Misselt, Karl; Robitaille, Thomas; Sewiło, Marta; Shiao, Bernie; Whitney, Barbara.
In: Astronomical Journal, Vol. 142, No. 4, 103, 10.2011.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Surveying the agents of galaxy evolution in the tidally stripped, low metallicity Small Magellanic Cloud (SAGE-SMC). II. Cool evolved stars
AU - Boyer, Martha L.
AU - Srinivasan, Sundar
AU - Van Loon, Jacco Th
AU - McDonald, Iain
AU - Meixner, Margaret
AU - Zaritsky, Dennis F
AU - Gordon, Karl D.
AU - Kemper, F.
AU - Babler, Brian
AU - Block, Miwa
AU - Bracker, Steve
AU - Engelbracht, Charles W.
AU - Hora, Joe
AU - Indebetouw, Remy
AU - Meade, Marilyn
AU - Misselt, Karl
AU - Robitaille, Thomas
AU - Sewiło, Marta
AU - Shiao, Bernie
AU - Whitney, Barbara
PY - 2011/10
Y1 - 2011/10
N2 - 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.
AB - 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.
KW - circumstellar matter
KW - Magellanic Clouds
KW - stars: AGB and post-AGB
KW - stars: carbon
KW - stars: mass-loss
KW - supergiants
UR - http://www.scopus.com/inward/record.url?scp=80054021488&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80054021488&partnerID=8YFLogxK
U2 - 10.1088/0004-6256/142/4/103
DO - 10.1088/0004-6256/142/4/103
M3 - Article
AN - SCOPUS:80054021488
VL - 142
JO - Astronomical Journal
JF - Astronomical Journal
SN - 0004-6256
IS - 4
M1 - 103
ER -