2011ApJ...739L..27P

We present Expanded Very Large Array (EVLA) D-array observations of the 21 cm line of neutral hydrogen (H I) of CIG 292, an isolated SA(s)b galaxy at a distance of ∼24.3 Mpc. From previous H I single dish observations the galaxy was known to have a mildly asymmetric H I profile (A_flux= 1.23 ±0.3). Our EVLA observations show there is ∼12% more H I projected south of the optical center (approaching velocities) than in the north (receding velocities), despite the H I extending ∼16% further to the north than the south. The H I projected within the optical disk must have been perturbed within the H I relaxation time (∼10⁸ yr) which implies that this cannot have been caused by any of the three nearest companions, as their distance (∼0.5 Mpc) is too large. Neither H I-rich companions nor tidal tails were found within our field of view and velocity range covered. Our kinematical data suggest that the inner part harbors an oval distortion whereas the outer regions show signs of a modest warp. The mild asymmetry in the H I global profile thus actually masks stronger asymmetries in the two-dimensional distributions of gas and star-forming regions in this galaxy. Since the galaxy is isolated, this must predominantly be due to processes related to its formation and secular evolution.