Jönsson, H.; Allende Prieto, Carlos; Holtzman, Jon A.; Feuillet, Diane K.; Hawkins, Keith; Cunha, Katia; Mészáros, Szabolcs; Hasselquist, Sten; Fernández-Trincado, J. G.; García-Hernández, D. A.; Bizyaev, Dmitry; Carrera, Ricardo; Majewski, Steven R.; Pinsonneault, Marc H.; Shetrone, Matthew; Smith, Verne; Sobeck, Jennifer; Souto, Diogo; Stringfellow, Guy S.; Teske, Johanna; Zamora, O.
Bibliographical reference
The Astronomical Journal, Volume 156, Issue 3, article id. 126, 25 pp. (2018).
Description
Data from the SDSS-IV/Apache Point Observatory Galactic Evolution
Experiment (APOGEE-2) have been released as part of SDSS Data Releases
13 (DR13) and 14 (DR14). These include high-resolution H-band spectra,
radial velocities, and derived stellar parameters and abundances. DR13,
released in 2016 August, contained APOGEE data for roughly 150,000
stars, and DR14, released in 2017 August, added about 110,000 more.
Stellar parameters and abundances have been derived with an automated
pipeline, the APOGEE Stellar Parameter and Chemical Abundance Pipeline
(ASPCAP). We evaluate the performance of this pipeline by comparing the
derived stellar parameters and abundances to those inferred from optical
spectra and analysis for several hundred stars. For most
elements—C, Na, Mg, Al, Si, S, Ca, Cr, Mn, Ni—the DR14
ASPCAP analyses have systematic differences with the comparisons samples
of less than 0.05 dex (median), and random differences of less than 0.15
dex (standard deviation). These differences are a combination of the
uncertainties in both the comparison samples as well as the ASPCAP
analysis. Compared to the references, magnesium is the most accurate
alpha-element derived by ASPCAP, and shows a very clear thin/thick disk
separation, while nickel is the most accurate iron-peak element (besides
iron itself).
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