Bayesian distances and extinctions for giants observed by Kepler and APOGEE
Abstract
We present a first determination of distances and extinctions for individual stars in the first release of the APOKASC catalogue, built from the joint efforts of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and the Kepler Asteroseismic Science Consortium (KASC). Our method takes into account the spectroscopic constraints derived from the APOGEE Stellar Parameters and Chemical Abundances Pipeline, together with the asteroseismic parameters from KASC. These parameters are then employed to estimate intrinsic stellar properties, including absolute magnitudes, using the Bayesian tool PARAM. We then find the distance and extinction that best fit the observed photometry in SDSS, 2MASS, and WISE passbands. The first 1989 giants targeted by APOKASC are found at typical distances between 0.5 and 5 kpc, with individual uncertainties of just ~1.8 per cent. Our extinction estimates are systematically smaller than provided in the Kepler Input Catalogue and by the Schlegel, Finkbeiner and Davis maps. Distances to individual stars in the NGC 6791 and NGC 6819 star clusters agree to within their credible intervals. Comparison with the APOGEE red clump and SAGA catalogues provide another useful check, exhibiting agreement with our measurements to within a few percent. Overall, present methods seem to provide excellent distance and extinction determinations for the bulk of the APOKASC sample. Approximately one third of the stars present broad or multiple-peaked probability density functions and hence increased uncertainties. Uncertainties are expected to be reduced in future releases of the catalogue, when a larger fraction of the stars will have seismically-determined evolutionary status classifications.
Keywords
Cite
@article{arxiv.1410.1350,
title = {Bayesian distances and extinctions for giants observed by Kepler and APOGEE},
author = {Thaíse S. Rodrigues and Léo Girardi and Andrea Miglio and Diego Bossini and Jo Bovy and Courtney Epstein and Marc H. Pinsonneault and Dennis Stello and Gail Zasowski and Carlos Allende Prieto and William J. Chaplin and Saskia Hekker and Jennifer A. Johnson and Szabolcs Mészáros and Benoît Mosser and Friedrich Anders and Sarbani Basu and Timothy C. Beers and Cristina Chiappini and Luiz A. N. da Costa and Yvonne Elsworth and Rafael A. García and Ana E. García Pérez and Fred R. Hearty and Marcio A. G. Maia and Steven R. Majewski and Savita Mathur and Josefina Montalbán and David L. Nidever and Basilio Santiago and Mathias Schultheis and Aldo Serenelli and Matthew Shetrone},
journal= {arXiv preprint arXiv:1410.1350},
year = {2016}
}
Comments
21 pages, 20 figures, accepted for publication in MNRAS