A. B. A. Queiroz, F. Anders, C. Chiappini, A. Khalatyan, B. X. Santiago, M. Steinmetz, M. Valentini, A. Miglio, D. Bossini, B. Barbuy, I. Minchev, D. Minniti, D. A. GarcŪa HernŠndez, M. Schultheis, R. L. Beaton, T. C. Beers, D. Bizyaev, J. R. Brownstein, K. Cunha, J. G. FernŠndez-Trincado, P. M. Frinchaboy, R. R. Lane, S. R. Majewski, D. Nataf, C. Nitschelm, K. Pan, A. Roman-Lopes, J. Sobeck, O. Zamora
We combine high-resolution spectroscopic data from APOGEE-2 survey Data Release 16 (DR16) with broad-band photometric data from several sources as well as parallaxes from Gaia Data Release 2 (DR2). Using the Bayesian isochrone-fitting code StarHorse, we derived the distances, extinctions, and astrophysical parameters for around 388 815 APOGEE stars. We achieve typical distance uncertainties of ∼6% for APOGEE giants, ∼2% for APOGEE dwarfs, and extinction uncertainties of ∼0.07 mag, when all photometric information is available, and ∼0.17 mag if optical photometry is missing. StarHorse uncertainties vary with the input spectroscopic catalogue, available photometry, and parallax uncertainties. To illustrate the impact of our results, we show that thanks to Gaia DR2 and the now larger sky coverage of APOGEE-2 (including APOGEE-South), we obtain an extended map of the Galactic plane. We thereby provide an unprecedented coverage of the disc close to the Galactic mid-plane (|ZGal| < 1 kpc) from the Galactic centre out to RGal ∼ 20 kpc. The improvements in statistics as well as distance and extinction uncertainties unveil the presence of the bar in stellar density and the striking chemical duality in the innermost regions of the disc, which now clearly extend to the inner bulge. We complement this paper with distances and extinctions for stars in other public released spectroscopic surveys: 324 999 in GALAH DR2, 4 928 715 in LAMOST DR5, 408 894 in RAVE DR6, and 6095 in GES DR3.
stars: distances; stars: fundamental parameters; stars: statistics; Galaxy: general; Galaxy: disk; Galaxy: stellar content; Astrophysics - Astrophysics of Galaxies
Data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (184.108.40.206) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/638/A76
Astronomy and Astrophysics
Volume 638, Article Number A76, Number of pages 31