Holtzman, J. A.; Hasselquist, Sten; Shetrone, Matthew; Cunha, Katia; Allende Prieto, C.; Anguiano, Borja; Bizyaev, Dmitry; Bovy, Jo; Casey, Andrew; Edvardsson, Bengt; Johnson, Jennifer A.; Jönsson, Henrik; Meszaros, Szabolcs; Smith, Verne V.; Sobeck, Jennifer; Zamora, O.; Chojnowski, S. Drew; Fernandez-Trincado, Jose; Garcia-Hernandez, D. A.; Majewski, Steven R.; Pinsonneault, Marc; Souto, Diogo; Stringfellow, Guy S.; Tayar, Jamie; Troup, Nicholas; Zasowski, Gail
Bibliographical reference
The Astronomical Journal, Volume 156, Issue 3, article id. 125, 24 pp. (2018).
Description
The data and analysis methodology used for the SDSS/APOGEE Data Releases
13 and 14 are described, highlighting differences from the DR12 analysis
presented in Holtzman et al. Some improvement in the handling of
telluric absorption and persistence is demonstrated. The derivation and
calibration of stellar parameters, chemical abundances, and respective
uncertainties are described, along with the ranges over which
calibration was performed. Some known issues with the public data
related to the calibration of the effective temperatures (DR13), surface
gravity (DR13 and DR14), and C and N abundances for dwarfs (DR13 and
DR14) are highlighted. We discuss how results from a data-driven
technique, The Cannon, are included in DR14 and compare those with
results from the APOGEE Stellar Parameters and Chemical Abundances
Pipeline. We describe how using The Cannon in a mode that restricts the
abundance analysis of each element to regions of the spectrum with known
features from that element leads to Cannon abundances can lead to
significantly different results for some elements than when all regions
of the spectrum are used to derive abundances.
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