Derivation of parameters for 3748 FGK stars using H-band spectra from APOGEE Data Release 14^⋆

¹ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
e-mail: pedro.sarmento@astro.up.pt
² Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
³ Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, Chile
⁴ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA

Received: 11 July 2019
Accepted: 23 December 2019

Abstract

Context. The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has observed the H-band spectra of over 200 000 stars with R ∼ 22 000.

Aims. The main motivation for this work is to test an alternative method to the standard APOGEE pipeline (APOGEE Stellar Parameter and Chemical Abundances Pipeline, ASPCAP) to derive parameters in the near-infrared for FGK dwarfs.

Methods. iSpec and Turbospectrum are used to generate synthetic spectra matching APOGEE observations and to determine the parameters through χ² minimization.

Results. We present spectroscopic parameters (T_eff, [M/H], log g, v_mic) for a sample of 3748 main-sequence and subgiant FGK stars, obtained from their APOGEE H-band spectra.

Conclusions. We compare our output parameters with the ones obtained with ASPCAP for the same stellar spectrum, and find that the values agree within the expected uncertainties. A comparison with the optical samples California Planet Survey, High Accuracy Radial Velocity Planet Searcher – Guaranteed Time Observations, and PASTEL is also available, and median differences below 10 K for T_eff and 0.2 dex for [M/H] are found. Reasons for these differences are explored. The full H-band line list, the line selection for the synthesis, and the synthesized spectra are available at the CDS, as are the calculated parameters and their estimated uncertainties.