Testing the asteroseismic mass scale using metal-poor stars characterized with APOGEE and Kepler

Research output: Contribution to journalArticlepeer-review

Authors

  • Courtney R. Epstein
  • Jennifer A. Johnson
  • Matthew Shetrone
  • Benoît Mosser
  • Saskia Hekker
  • Jamie Tayar
  • Paul Harding
  • Marc Pinsonneault
  • Víctor Silva Aguirre
  • Sarbani Basu
  • Timothy C. Beers
  • Dmitry Bizyaev
  • Timothy R. Bedding
  • Peter M. Frinchaboy
  • Rafael A. García
  • Ana E García Pérez
  • Fred R. Hearty
  • Daniel Huber
  • Inese I. Ivans
  • Steven R. Majewski
  • Savita Mathur
  • David Nidever
  • Aldo Serenelli
  • Ricardo P. Schiavon
  • Donald P. Schneider
  • Ralph Schönrich
  • Jennifer S. Sobeck
  • Keivan G. Stassun
  • Dennis Stello
  • Gail Zasowski

Colleges, School and Institutes

External organisations

  • University of Texas at Austin
  • Texas Christian University
  • Johns Hopkins University
  • University of Virginia
  • Aarhus Universitet
  • Ohio State University
  • University of Sydney
  • University of Michigan
  • Yale University
  • Pennsylvania State University
  • Northwestern University
  • University of Oxford
  • Vanderbilt University
  • Liverpool John Moores University
  • Observatoire de Paris, LESIA, CNRS UMR 8109, 92195 Meudon, France
  • TUBS, Braunschweig, D-38106, and Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany); AH(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
  • Université Paris Denis Diderot
  • University of Texas
  • Case Western Reserve University
  • National Optical Astronomy Observatory
  • Apache Point Observatory
  • Department of Physics and Astronomy, Texas Christian University (TCU)
  • NASA Ames Research Center
  • University of Utah
  • Space Science Institute
  • Institute of Space Sciences (IEEC-CSIC), Campus UAB, Fac. Cincies, Torre C5 Parell 2
  • University of Chicago

Abstract

Fundamental stellar properties, such as mass, radius, and age, can be inferred using asteroseismology. Cool stars with convective envelopes have turbulent motions that can stochastically drive and damp pulsations. The properties of the oscillation frequency power spectrum can be tied to mass and radius through solar-scaled asteroseismic relations. Stellar properties derived using these scaling relations need verification over a range of metallicities. Because the age and mass of halo stars are well-constrained by astrophysical priors, they provide an independent, empirical check on asteroseismic mass estimates in the low-metallicity regime. We identify nine metal-poor red giants (including six stars that are kinematically associated with the halo) from a sample observed by both the Kepler space telescope and the Sloan Digital Sky Survey-III APOGEE spectroscopic survey. We compare masses inferred using asteroseismology to those expected for halo and thick-disk stars. Although our sample is small, standard scaling relations, combined with asteroseismic parameters from the APOKASC Catalog, produce masses that are systematically higher (<ΔM > =0.17 ± 0.05 M) than astrophysical expectations. The magnitude of the mass discrepancy is reduced by known theoretical corrections to the measured large frequency separation scaling relationship. Using alternative methods for measuring asteroseismic parameters induces systematic shifts at the 0.04 M level. We also compare published asteroseismic analyses with scaling relationship masses to examine the impact of using the frequency of maximum power as a constraint. Upcoming APOKASC observations will provide a larger sample of 100 metal-poor stars, important for detailed asteroseismic characterization of Galactic stellar populations.

Details

Original languageEnglish
Article numberL28
JournalAstrophysical Journal Letters
Volume785
Issue number2
Publication statusPublished - 20 Apr 2014

Keywords

  • asteroseismology, Galaxy: halo, stars: fundamental parameters