Comparison of the Asteroseismic Mass Scale of Red Clump Giants with Photometric Mass Estimates
- 주제(키워드) open clusters and associations: individual (M67 , NGC 6791) , stars: evolution , stars: horizontal-branch , stars: mass-loss
- 주제(기타) Astronomy & Astrophysics
- 설명문(일반) [An, Deokkeun] Ewha Womans Univ, Dept Sci Educ, 52 Ewhayeodae Gil, Seoul 03760, South Korea; [Pinsonneault, Marc H.; Terndrup, Donald M.] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA; [Chung, Chul] Yonsei Univ, Dept Astron, Seoul 03722, South Korea; [Chung, Chul] Yonsei Univ, Ctr Galaxy Evolut Res, Seoul 03722, South Korea
- 등재 SCIE, SCOPUS
- OA유형 Green Submitted
- 발행기관 IOP PUBLISHING LTD
- 발행년도 2019
- URI http://www.dcollection.net/handler/ewha/000000160191
- 본문언어 영어
- Published As http://dx.doi.org/10.3847/1538-4357/ab23ed
초록/요약
Asteroseismology can provide joint constraints on masses and radii of individual stars. While this approach has been extensively tested for red giant branch (RGB) stars, it has been more difficult to test for helium core-burning red clump (RC) giants because of the lack of fundamental calibrators. To provide independent mass estimates, we utilize a number of widely used horizontal-branch models in the literature and derive photometric masses from a comparison with griBVI(C)JHK(s) photometry. Our selected models disagree with each other on the predicted mass-luminosity-temperature relation. We adopt first-order corrections on colors and magnitudes to minimize the dispersion between different models by forcing models to match the observed location in the solar-metallicity cluster M67. Even for these calibrated models, however, the internal consistency between models deteriorates at higher metallicities, and photometric masses become smaller than asteroseismic masses, as seen from metal-rich field RC stars with Gaia parallaxes. Similarly, the average photometric mass for metal-rich NGC. 6791 stars ranges from 0.7 to 1.1 M-circle dot, depending on the specific set of models employed. An ensemble average of the photometric masses (0.88 +/- 0.16 M-circle dot) in NGC 6791 is marginally consistent with the asteroseismic mass (1.16 +/- 0.04 M-circle dot). There is a clear tension between the masses that one would predict from photometry for metal-rich field RC stars, asteroseismic masses, and those that would be expected from the ages of stars in the Galactic disk populations and canonical RGB mass loss. We conclude that standard RC models need to be reexamined in light of these powerful new data sets.
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