A catalog of 1.5273 micron diffuse interstellar bands based on APOGEE hot telluric calibrators

TL;DR

This paper presents a large, high-quality catalog of 1.5273 micron diffuse interstellar band measurements from APOGEE hot telluric calibrators, enabling improved 3D mapping of the Galactic ISM.

Contribution

The authors developed a new method to extract DIBs from stellar spectra and created a comprehensive catalog of ~6700 measurements, enhancing ISM studies.

Findings

Extracted ~6700 DIB measurements from ~16,000 spectra.

Applied new selection criteria for robust DIB detection.

Provided a catalog with equivalent widths, wavelengths, and widths of DIBs.

Abstract

High resolution stellar spectroscopic surveys provide massive amounts of diffuse interstellar bands (DIBs) measurements. Data can be used to study the distribution of the DIB carriers and those environmental conditions that favor their formation. In parallel, recent studies have also proved that DIBs extracted from stellar spectra constitute new tools for building the 3D structure of the Galactic Interstellar Medium (ISM). The amount of details on the structure depends directly on the quantity of available lines of sight (LOS). Therefore there is a need to construct databases of high-quality DIB measurements as large as possible. We aim at providing the community with a catalog of high-quality measurements of the 1.5273 micron DIB towards a large fraction of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) hot stars observed to correct for the telluric absorption and not used for ISM studies so far. This catalog would complement the extensive database recently extracted from the APOGEE observations and used for 3D ISM mapping. We devised a method to fit the stellar continuum of the hot calibration stars and extracted the DIB from the normalized spectrum. Severe selection criteria based on the absorption characteristics are applied to the results. In particular limiting constraints on the DIB widths and Doppler shifts are deduced from the HI 21 cm measurements, following a new technique of decomposition of the emission spectra. From ~16 000 available hot telluric spectra we have extracted ~ 6700 DIB measurements and their associated uncertainties. The statistical properties of the extracted absorptions are examined and our selection criteria are shown to provide a robust dataset. The resulting catalog contains the DIB total equivalent widths, central wavelengths and widths. We briefly illustrate its potential use for the stellar and interstellar communities.