ABSTRACT

The effect of an active nucleus on its host galaxy (Shanbhag 1991; Shanbhag and Kembhavi 1988; Begelman 1985) can be large. In particular, heating by the radiation from the nucleus strongly affects the hydrodynamic evolution of gas in the interstellar medium (ISM) of the host galaxy. Enhanced star formation activity on a galaxy-wide scale can be induced. The proximity of NGC 1068 makes it an interesting candidate to study such interaction. The model explains extended X-ray emission and some properties of the diffuse ionized medium (DIM) observed in the galaxy.

INTRODUCTION

NGC 1068 is a nearby Sy 1 galaxy disguised as Sy 2 with its “buried” nucleus obscured from direct view (Antonucci and Miller 1985). The unobscured solid angle as seen from the nucleus, is inferred to be ∼ π (Krolik and Begelman 1986). The emission from the nucleus is modeled by bipolar conical outflows of opening angle ≃ 82° with the symmetry axis inclined to the plane of the galaxy by ≃ 35° (Cecil et al. 1990). Its inferred intrinsic luminosity (Sokolowski et al. 1991) is ≃ 7 x 1043 erg s-1. Many observations (Bergeron et al. 1989; Cecil et al. 1990) show existence of activity in the direction of the cone open angle; implying a connection with the active nucleus. The motivation behind this paper is to understand the nature of such interaction.