Calibrations of Atmospheric Parameters Obtained from the First Year of SDSS-III APOGEE Observations

Author(s)

Sz. Mészáros, J. Holtzman, A. E. García Pérez, C. Allende Prieto, R. P. Schiavon, S. Basu, D. Bizyaev, W. J. Chaplin, S. D. Chojnowski, K. Cunha, Y. Elsworth, C. Epstein, P. M. Frinchaboy, R. A. García, F. R. Hearty, S. Hekker, T. Kallinger, L. Koesterke, S. L. Martell, D. Nidever, M. H. Pinsonneault, J. O'Connell, M. Shetrone, V. V. Smith, G. Zasowski

Abstract

The Sloan Digital Sky Survey III (SDSS-III) Apache Point Observatory

Galactic Evolution Experiment (APOGEE) is a three-year survey that is

collecting 105 high-resolution spectra in the near-IR across

multiple Galactic populations. To derive stellar parameters and chemical

compositions from this massive data set, the APOGEE Stellar Parameters

and Chemical Abundances Pipeline (ASPCAP) has been developed. Here, we

describe empirical calibrations of stellar parameters presented in the

first SDSS-III APOGEE data release (DR10). These calibrations were

enabled by observations of 559 stars in 20 globular and open clusters.

The cluster observations were supplemented by observations of stars in

NASA's Kepler field that have well determined surface gravities from

asteroseismic analysis. We discuss the accuracy and precision of the

derived stellar parameters, considering especially effective

temperature, surface gravity, and metallicity; we also briefly discuss

the derived results for the abundances of the α-elements, carbon,

and nitrogen. Overall, we find that ASPCAP achieves reasonably accurate

results for temperature and metallicity, but suffers from systematic

errors in surface gravity. We derive calibration relations that bring

the raw ASPCAP results into better agreement with independently

determined stellar parameters. The internal scatter of ASPCAP parameters

within clusters suggests that metallicities are measured with a

precision better than 0.1 dex, effective temperatures better than 150 K,

and surface gravities better than 0.2 dex. The understanding provided by

the clusters and Kepler giants on the current accuracy and precision

will be invaluable for future improvements of the pipeline.

Organisation(s)

Department of Astrophysics

External organisation(s)

University of Arizona, Ohio State University, University of Birmingham, Institute of Astrophysics of the Canary Islands, University of La Laguna, New Mexico State University, University of Virginia, Liverpool John Moores University (LJMU), Yale University, Apache Point Observatory, Observatório Nacional/MCT, Texas Christian University, Université Paris VII - Paris-Diderot, University of Amsterdam (UvA), University of Texas, Austin, Australian Astronomical Observatory, University of Michigan, National Optical Astronomy Observatory, Tucson

Journal

The Astrophysical Journal: an international review of astronomy and astronomical physics

Volume

146

No. of pages

19

ISSN

0004-637X

DOI

https://doi.org/10.1088/0004-6256/146/5/133

Publication date

11-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics, 103003 Astronomy

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/82c11d89-d3c1-41ed-bad5-2bcf332cd2dd