HI absorption at the center of NGC2146
  We present 1.4 GHz HI absorption line observations towards the starburst in NGC2146, made with the VLA and MERLIN. The HI gas has a rotating disk/ring structure with column densities between 6 and 18 x 10(21) atoms cm(-2). The HI absorption has a uniform spatial and velocity distribution, and does not reveal any anomalous material concentration or velocity in the central region of the galaxy which might indicate an encounter with another galaxy or a far-evolved merger. We conclude that the signs of an encounter causing the starburst should be searched for in the outer regions of the galaxy. 
A. Tarchi, A. Greve, A. B. Peck, N. Neininger, K. A. Wills, A. Pedlar,   U. Klein