Interaction Between NGC 5394 and NGC 5395

The spiral galaxies NGC 5394/95 (at a distance of 47 Mpc) are involved in a recent, close, nonmerging encounter. The smaller galaxy, NGC 5394, has two long, fairly symmetric, open tidal arms (see Figure 1); in numerical simulations, this type of structure results from a close, prograde, nearly in-plane encounter. To study this galaxy pair, we used the VLA to obtain HI (21 cm line) and radio continuum data, the Maryland-Caltech Fabry-Perot camera to obtain Ha data, the 2.1m telescope at KPNO, the Fick observatory 0.6 m telescope, and the Burrell-Schmidt telescope to take optical and near-infrared images, and Onsala Space Observatory for CO J=1-0 observations.