2008ApJ...684L..17B

We present high spatial resolution 21 cm H I observations of EA01A and EA01B, a pair of interacting poststarburst, or E+A, galaxies at z=0.0746. Based on optical HST/WFPC2 images, both galaxies are known to display disturbed morphologies. They also appear to be linked by a bridge of stars. Previous H I observations by Chang et al. in 2001 had already uncovered sizable quantities of neutral gas in or near these galaxies, but they lacked the spatial resolution to locate the gas with any precision within this galactic binary system. We have analyzed deep, high-resolution archival VLA observations of the couple. We find evidence for three gaseous tidal tails: one connected to EA01A and two emanating from EA01B. These findings confirm, independently from the optical imaging, that (i) EA01A and EA01B are actively interacting, and that, as a consequence, the starbursts that occurred in these galaxies were most likely triggered by this interaction, and that (ii) 6.6±0.9x10⁹ M_☉ of neutral gas are still present in the immediate vicinity of the optical bodies of both galaxies. The H I column density is lowest at the optical positions of the galaxies, suggesting that most of the neutral gas that is visible in our maps is associated with the tidal arms and not with the galaxies themselves. This might provide an explanation for the apparent lack of ongoing star formation in these galaxies.