[ITAL]HUBBLE SPACE TELESCOPE[/ITAL][ITAL]Hubble Space Telescope[/ITAL] Observations of the C[CLC]f[/CLC]A Seyfert 2 Galaxies: The Fueling of Active Galactic Nuclei

We present an investigation of possible fueling mechanisms operating in theinner kiloparsec of Seyfert galaxies. We analyze visible and near-infraredHubble Space Telescope images of 24 Seyfert 2s from the CfA Redshift Surveysample. In particular, we are searching for the morphological signatures ofdynamical processes reponsible for transporting gas from kiloparsec scales intothe nucleus. The circumnuclear regions are very rich in gas and dust, oftentaking the form of nuclear spiral dust lanes on scales of a few hundredparsecs. While these nuclear spirals are found in 20 of our 24 Seyferts, wefind only 5 nuclear bars among the entire sample, strongly reinforcing theconclusions of other investigators that nuclear bars are not the primary meansof transporting this material into the nucleus. An estimate of the gas densityin the nuclear spirals based on extinction measurements suggests that thenuclear spiral dust lanes are probably shocks in nuclear gas disks that are notstrongly self-gravitating. Since shocks can dissipate energy and angularmomentum, these spiral dust lanes may be the channels by which gas from thehost galaxy disks is being fed into the central engines.