A Search for Extragalactic Diffuse Interstellar Bands

Abstract

Diffuse interstellar bands (DIBs) are puzzling absorption features that can be found in the spectra of reddened objects in our Galaxy, as well as in other observed galaxies. Although we still know too little of the carriers of DIBs, the numerous features along the optical and near infrared wavelengths and the consistency of their measured properties make DIBs potentially promising interstellar material tracers. DIBs studies are mostly based on stellar spectra in our Galaxy, but since DIBs can also be found in other galaxies, we search for DIBs in the spectra of nearby galaxies by perusing Sydney-AAO Multi-object Integral-field unit (SAMI) data. We demonstrate DIB measurement by performing an automated fitting of a combination of a smooth continuum and a model of DIB profile to the spectrum. This preliminary result will be an important input to consider in drawing conclusion about DIBs and their environments. Show more