HIFI Results on the Superbubble of NGC 3079

Summary

ABSTRACT

The Hawaii Imaging Fabry-Perot Interferometer (HIFI) was used to produce a large data cube of the edge-on SBc galaxy NGC 3079 covering Hα + [Nil] λλ6548, 6583. The complete two-dimensional coverage of the Fabry-Perot data allowed us to derive the general flow pattern of the nuclear gas making up the superbubble in this object. Comparisons of our results with the well-known outflows in the Seyfert galaxy NGC 1068 and the starburst galaxy M82 indicate that the mass of entrained material is similar in these three galaxies, but that the kinetic energy involved in the outflow of NGC 3079 is at least an order of magnitude larger than in NGC 1068 and M82. The active nucleus in NGC 3079 is probably powering some of the outflow.

INTRODUCTION

Recent observations suggest that a violent outflow is taking place in the core of the edge-on SB(s)c galaxy NGC 3079. The optical line emission in the nucleus is LINER-like (Heckman 1980), and Hα presents faint, broad wings (Stauffer 1982; Keel 1983) reminiscent of low-luminosity Seyfert 1 galaxies. On closer inspection, however, the line emission responsible for the broad wings in the Hα profile is produced by a complex of extranuclear high-velocity clouds (Heckman, Armus, and Miley 1990 [HAM]; Filippenko and Sargent 1992 [FS]) which coincides in position with a looplike structure first discovered in Hα + [NII] images (Ford et al. 1986).