We present observations which probe the small-scale structure of the interstellar medium using diffuse interstellar bands (DIBs). Towards HD 168075/6 in the Eagle Nebula, significant differences in DIB absorption are found between the two lines of sight, which are separated by 0.25 pc, and {\lambda}5797 exhibits a velocity shift. Similar data are presented for four stars in the {\mu} Sgr system. We also present a search for variations in DIB absorption towards {\kappa} Vel, where the atomic lines are known to vary on scales of ~10 AU. Observations separated by ~9 yr yielded no evidence for changes in DIB absorption strength over this scale, but do reveal an unusual DIB spectrum.
@article{arxiv.1307.3798,
title = {Diffuse interstellar bands as probes of small-scale interstellar structure},
author = {Keith T. Smith and Martin A. Cordiner and Peter J. Sarre},
journal= {arXiv preprint arXiv:1307.3798},
year = {2017}
}
Comments
3 pages, 3 figures. Poster presentation to be published in Proc. IAU Symposium 297, The Diffuse Interstellar Bands, eds. J. Cami & N. Cox