IGRINS Spectral Library

TL;DR

This paper introduces a high-resolution near-infrared spectral library of 84 stars, providing spectral lines, indices, and empirical relations to determine stellar parameters without models.

Contribution

The first high-resolution, high S/N near-infrared spectral library with empirical relations for stellar parameters across various spectral types.

Findings

Spectral lines sensitive to temperature and gravity identified.

Empirical relations between line indices and stellar parameters established.

Library includes flux-calibrated, telluric-corrected spectra of 84 stars.

Abstract

We present a library of high-resolution (R $\equiv$ $\lambda$/$\Delta$$\lambda$ $\sim$ 45,000) and high signal-to-noise ratio (S/N $\geq$ 200) near-infrared spectra for stars of a wide range of spectral types and luminosity classes. The spectra were obtained with the Immersion GRating INfrared Spectrograph (IGRINS) covering the full range of the H (1.496-1.780 $\mu$m) and K (2.080-2.460 $\mu$m) atmospheric windows. The targets were primarily selected for being MK standard stars covering a wide range of effective temperatures and surface gravities with metallicities close to the Solar value. Currently, the library includes flux-calibrated and telluric-absorption-corrected spectra of 84 stars, with prospects for expansion to provide denser coverage of the parametric space. Throughout the H and K atmospheric windows, we identified spectral lines that are sensitive to $T_\mathrm{eff}$ or $\log g$ and defined corresponding spectral indices. We also provide their equivalent widths. For those indices, we derive empirical relations between the measured equivalent widths and the stellar atmospheric parameters. Therefore, the derived empirical equations can be used to calculate $T_\mathrm{eff}$ and $\log g$ of a star without requiring stellar atmospheric models.