DIB Measurements in 25 atlas sightlines

Twenty-five medium to highly reddened sight lines were selected, sampling a variety of spectral types of the background star and the interstellar environments. The median signal-to-noise ratio (S/N) of these spectra is ~1300 around 6400{AA}.

Compared to the Atlas Catalog, 22 new DIBs were found, and the boundaries of 27 (sets of) DIBs were adjusted, resulting in an updated catalog containing 559 DIBs that we refer to as the Apache Point Observatory Catalog of Optical Diffuse Interstellar Bands. Measurements were then made based on this catalog. We found our survey most sensitive between 5500 and 7000{AA}, due largely to the local S/N of the spectra, the relative absence of interfering stellar lines, and the weakness of telluric residuals.