Automated measurements of diffuse interstellar bands in early-type star spectra Correlations with the Color Excess

TL;DR

This paper introduces an automated method for measuring diffuse interstellar bands in stellar spectra, applied to high-resolution data, enabling efficient analysis of interstellar environments and cloud locations.

Contribution

The study develops and applies a fully automated DIB measurement technique tailored for early-type stars in large stellar surveys, improving efficiency and consistency.

Findings

Automated measurements for 16 DIBs in optical spectra.

Application to 130 high-resolution stellar spectra.

Comparison with other measurement methods shows good agreement.

Abstract

Stellar spectroscopic surveys may bring useful statistical information on the links between Diffuse Interstellar Bands (DIBs) and interstellar environment. DIB databases can also be used as a complementary tool for locating interstellar (IS) clouds. Our goal is to develop fully automated methods of DIB measurements to be applied to extensive data from stellar surveys. We present a method appropriate for early-type nearby stars, its application to high-resolution spectra of 130 targets recorded with ESO FEROS spectrograph, and comparisons with other determinations. Using a DIB average profile deduced from the most reddened stars, we performed an automated fitting of a combination of a smooth stellar continuum, the DIB profile, and, when necessary, a synthetic telluric transmission. Measurements are presented for 16 DIBs in the optical domain that could be extracted automatically: 4726.8, 4762.6, 4963.9, 5780.4, 5797.1, 5849.8, 6089.8, 6196.0, 6203.0-6204.5, 6269.8, 6283.8, 6379.3, 6445.3, 6613.6, 6660.7, and 6699.3 {\AA}.