Speaker
Dr
Alexey Mints
(Max Planck Institute for Solar System Research)
Description
In an effort to unify the spectroscopic data of different surveys for Galactic archaeology purposes we developed and made public our Unified tool for Distance, Age and Mass estimation (UniDAM). This tool is based on a Bayesian method to compute probability density functions of distance modulus, log(age) and mass using spectroscopic parameters (effective temperature, surface gravity and metallicity), infrared photometry (2MASS and AllWISE) and PARSEC isochrones. Here we present the result from UniDAM with Gaia parallaxes incorporated consistently. For over 100,000 LAMOST stars we have Gaia-TGAS parallaxes that we can use to improve distance modulus and log(age) estimates. The use of parallaxes allows us to improve our age and distance estimates
substantially - by about 30% in log(age) and about 50% in distance modulus. We also show that further improvements can be expected from further Gaia data releases, bringing log(age) uncertainties to about 0.1 dex and distance modulus uncertainties downto 0.01 mag. We show that for the most distant stars in LAMOST, spectrophotometric estimates of distance modulus will have higher precision even than those from end-of-mission Gaia parallaxes.
Primary author
Dr
Alexey Mints
(Max Planck Institute for Solar System Research)
Co-author
Dr
Saskia Hekker
(Max Planck Institute for Solar System Research)
