Asteroseismology and Gaia: Testing Scaling Relations Using 2200 Kepler Stars with TGAS Parallaxes
- Institute for Astronomy, University of Hawai‘i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
- Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States)
- Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)
- Institute of Space Sciences (IEEC-CSIC), Campus UAB, Carrer de Can Magrans S/N, E-08193, Barcelona (Spain)
- Vanderbilt University, Department of Physics and Astronomy, 6301 Stevenson Center Lane, Nashville, TN 37235 (United States)
- School of Physics, University of New South Wales, NSW 2052 (Australia)
- Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)
- Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia)
- Centre for Star and Planet Formation, Natural History Museum of Denmark and Niels Bohr Institute, University of Copenhagen, Oster Voldgade 5-7, DK-1350 Copenhagen K (Denmark)
- School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom)
- Laboratoire AIM, CEA/DRF-CNRS, Université Paris 7 Diderot, IRFU/SAp, Centre de Saclay, F-91191, Gif-sur-Yvette (France)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)
- Space Science Institute, 4750 Walnut street Suite 205, Boulder, CO 80301 (United States)
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 T{sub eff} 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{sub ⊙}. We find no significant offset for main-sequence (≲1.5 R{sub ⊙}) and low-luminosity RGB stars (≈3–8 R{sub ⊙}), but seismic radii appear to be systematically underestimated by ≈5% for subgiants (≈1.5–3 R{sub ⊙}). 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.
- OSTI ID:
- 22875977
- Journal Information:
- Astrophysical Journal, Vol. 844, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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