A survey of HI gas toward the Andromeda galaxy J. Kerp, P. M. W. Kalberla, N. Ben Bekhti, L. Flöer, D. Lenz and B. Winkel A&A, 589 (2016) A120 Published online: 22 April 2016 DOI: 10.1051/0004-6361/201526395