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Author
Girardi, LeoBoyer, Martha L.
Johnson, L. Clifton
Dalcanton, Julianne J.
Rosenfield, Philip
Seth, Anil C.
Skillman, Evan D.
Weisz, Daniel R.
Williams, Benjamin F.
Bhattacharya, Antara Raaghavi
Bressan, Alessandro
Caldwell, Nelson
Chen, Yang
Dolphin, Andrew E.
Fouesneau, Morgan
Goldman, Steven
Guhathakurta, Puragra
Marigo, Paola
Mukherjee, Sagnick
Pastorelli, Giada
Quirk, Amanda
Soraisam, Monika
Trabucchi, Michele
Affiliation
Univ Arizona, Steward ObservIssue Date
2020-09
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IOP PUBLISHING LTDCitation
Girardi, L., Boyer, M. L., Johnson, L. C., Dalcanton, J. J., Rosenfield, P., Seth, A. C., ... & Trabucchi, M. (2020). PHAT XX. AGB stars and other cool giants in M31 star clusters. The Astrophysical Journal, 901(1), 19.Journal
ASTROPHYSICAL JOURNALRights
© 2020. The American Astronomical Society. All rights reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
The presence of asymptotic giant branch (AGB) stars in clusters provides key constraints for stellar models, as has been demonstrated with historical data from the Magellanic Clouds. In this work, we look for candidate AGB stars in M31 star clusters from the Panchromatic Hubble Andromeda Treasury survey. Our photometric criteria selects stars brighter than the tip of the red giant branch, which includes the bulk of the thermally pulsing AGB stars as well as early-AGB stars and other luminous cool giants expected in young stellar populations (e.g., massive red supergiants, and intermediate-mass red helium-burning stars). The AGB stars can be differentiated, a posteriori, using the ages already estimated for our cluster sample. 937 candidates are found within the cluster aperture radii, half (similar to 450) of which are very likely cluster members. Cross-matching with additional databases reveals two carbon stars and 10 secure variables among them. The field-corrected age distribution reveals the presence of young supergiants peaking at ages smaller than 10(8) yr, followed by a long tail of AGB stars extending up to the oldest possible ages. This long tail reveals the general decrease in the numbers of AGB stars from initial values of similar to 50 x 10(-6)M(circle dot)(-1) at 10(8) yr down to similar to 5 x 10(-6)M(circle dot)(-1) at 10(10) yr. Theoretical models of near-solar metallicity reproduce this general trend, although with localized discrepancies over some age intervals, whose origin is not yet identified. The entire catalog is released together with finding charts to facilitate follow-up studies.Note
Immediate accessISSN
0004-637XEISSN
1538-4357Version
Final published versionae974a485f413a2113503eed53cd6c53
10.3847/1538-4357/abad3a