Narrow Diffuse Interstellar Bands: A Survey with Precise Wavelengths

Abstract

We present an atlas of 271 diffuse interstellar bands (DIBs) between 4460 and 8800 Å based on echelle spectra (R=45,000), of which more than 100 are new DIBs discovered in this survey. The atlas is restricted mostly to narrow features, and we describe the tests for an interstellar origin. The rest wavelength of each DIB was determined in a high-quality composite spectrum of the star HD 23180 using the interstellar Na I (D1 and D2) lines to establish the radial velocity of the single intervening cloud. DIB wavelengths are quoted to 0.01 Å and are probably accurate to ~0.1 Å. Other, weak DIBs found in the spectra of heavily reddened stars are included with a lower wavelength precision.