TY - JOUR
T1 - Asteroseismology and Gaia
T2 - Testing scaling relations using 2200 Kepler stars with TGAS parallaxes
AU - Huber, Daniel
AU - Zinn, Joel
AU - Bojsen-Hansen, Mathias
AU - Pinsonneault, Marc
AU - Sahlholdt, Christian
AU - Serenelli, Aldo
AU - Aguirre, Victor Silva
AU - Stassun, Keivan
AU - Stello, Dennis
AU - Tayar, Jamie
AU - Bastien, Fabienne
AU - Bedding, Timothy R.
AU - Buchhave, Lars A.
AU - Chaplin, William J.
AU - Davies, Guy R.
AU - García, Rafael A.
AU - Latham, David W.
AU - Mathur, Savita
AU - Mosser, Benoit
AU - Sharma, Sanjib
N1 - Publisher Copyright:
© 2017 The American Astronomical Society. All rights reserved.
PY - 2017
Y1 - 2017
N2 - We present a comparison of parallaxes and radii from asteroseismology and Gaia DR1 (TGAS) for 2200 Kepler stars spanning from the main sequence to the red-giant branch. We show that previously identified offsets between TGAS parallaxes and distances derived from asteroseismology and eclipsing binaries have likely been overestimated for parallaxes ≲5-10 mas (≈90%-98% of the TGAS sample). The observed differences in our sample can furthermore be partially compensated by adopting a hotter Teff scale (such as the infrared flux method) instead of spectroscopic temperatures for dwarfs and subgiants. Residual systematic differences are at the ≈2% level in parallax across three orders of magnitude. We use TGAS parallaxes to empirically demonstrate that asteroseismic radii are accurate to ≈5% or better for stars between ≈0.8-8 R⊙. We find no significant offset for main-sequence (≲1.5 R⊙) and low-luminosity RGB stars (≈3-8 R⊙), but seismic radii appear to be systematically underestimated by ≈5% for subgiants (≲1.5-3 R⊙). We find no systematic errors as a function of metallicity between [Fe H] ≈ -0.8 to +0.4 dex, and show tentative evidence that corrections to the scaling relation for the large frequency separation (Δν) improve the agreement with TGAS for RGB stars. Finally, we demonstrate that beyond ≈3 kpc asteroseismology will provide more precise distances than end-of-mission Gaia data, highlighting the synergy and complementary nature of Gaia and asteroseismology for studying galactic stellar populations.
AB - We present a comparison of parallaxes and radii from asteroseismology and Gaia DR1 (TGAS) for 2200 Kepler stars spanning from the main sequence to the red-giant branch. We show that previously identified offsets between TGAS parallaxes and distances derived from asteroseismology and eclipsing binaries have likely been overestimated for parallaxes ≲5-10 mas (≈90%-98% of the TGAS sample). The observed differences in our sample can furthermore be partially compensated by adopting a hotter Teff scale (such as the infrared flux method) instead of spectroscopic temperatures for dwarfs and subgiants. Residual systematic differences are at the ≈2% level in parallax across three orders of magnitude. We use TGAS parallaxes to empirically demonstrate that asteroseismic radii are accurate to ≈5% or better for stars between ≈0.8-8 R⊙. We find no significant offset for main-sequence (≲1.5 R⊙) and low-luminosity RGB stars (≈3-8 R⊙), but seismic radii appear to be systematically underestimated by ≈5% for subgiants (≲1.5-3 R⊙). We find no systematic errors as a function of metallicity between [Fe H] ≈ -0.8 to +0.4 dex, and show tentative evidence that corrections to the scaling relation for the large frequency separation (Δν) improve the agreement with TGAS for RGB stars. Finally, we demonstrate that beyond ≈3 kpc asteroseismology will provide more precise distances than end-of-mission Gaia data, highlighting the synergy and complementary nature of Gaia and asteroseismology for studying galactic stellar populations.
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U2 - 10.3847/1538-4357/aa75ca
DO - 10.3847/1538-4357/aa75ca
M3 - Article
AN - SCOPUS:85027411977
SN - 0004-637X
VL - 844
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 102
ER -