Quantifying the importance of ram-pressure stripping in a galaxy group at 100 Mpc

Abstract

We examine two members of the NGC 4065 group of galaxies: a bent-double (aka wide angle tail) radio source and an H I-deficient spiral galaxy. Models of the X-ray-emitting intragroup gas and the bent-double radio source, NGC 4061, are used to probe the density of intergalactic gas in this group. H I observations reveal an asymmetric, truncated distribution of H I in spiral galaxy, UGC 07049, and the accompanying radio continuum emission reveals strong star formation. We examine the effectiveness of ram-pressure stripping as a gas-removal mechanism and find that it alone cannot account for the H I deficiency that is observed in UGC 07049 unless this galaxy has passed through the core of the group with a velocity of 800 km/s. A combination of tidal and ram-pressure stripping are necessary to produce the H I deficiency and asymmetry in this galaxy.