Chemical Abundances in Field Red Giants from High-Resolution H-Band Spectra using the APOGEE Spectral Linelist

TL;DR

This study analyzes high-resolution H-band spectra of five red giants to determine their chemical abundances, demonstrating the APOGEE linelist's effectiveness for Galactic chemical evolution and stellar nucleosynthesis research.

Contribution

It provides the first detailed chemical abundance analysis of field red giants using APOGEE's high-resolution near-infrared spectra and confirms the linelist's reliability.

Findings

Consistent abundance measurements within ~0.1 dex compared to published values.

Demonstrates APOGEE spectral region's suitability for studying Galactic evolution.

Shows the linelist's effectiveness for probing stellar nucleosynthesis.

Abstract

High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS), are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the SDSS III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. Measured chemical abundances include the cosmochemically important isotopes 12C, 13C, 14N, and 16O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. A comparison of the abundances derived here with published values for these stars reveals consistent results to ~0.1 dex. The APOGEE spectral region and linelist is, thus, well-suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants using high-resolution spectroscopy.