Blue-shifted Broad Absorption Lines (BALs) detected in quasar's spectra are indicative of AGN outflows. We show, using 2D hydrodynamical simulations, that disruption of interstellar clouds by a fast AGN wind can lead to formation of cold, dense high speed blobs that give rise to broad absorption features in the transmission spectrum of the AGN continuum source. For a wind velocity of 0.1c and sufficiently high cloud density (nc < 104 cm−3, depending on size), absorption troughs with velocities up to about 3000 km s−1 can be produced. For slower winds and/or lower cloud density the anticipated velocity of the absorbing clouds should be smaller.
@article{arxiv.1910.09376,
title = {BALQSO Spectra Explained by Shock Disruption of Galactic Clouds},
author = {Meir Zeilig Hess and Amir Levinson and Xinfeng Xu and Nahum Arav},
journal= {arXiv preprint arXiv:1910.09376},
year = {2020}
}