1 research outputs found
Ultraviolet-Optical observations of the Seyfert 2 Galaxies NGC 7130, NGC 5135 and IC 3639: Implications for the Starburst-AGN Connection
We present and discuss HST (WFPC2 and FOC) images and UV GHRS spectra plus
ground-based near UV through to near IR spectra of three Seyfert 2 nuclei (NGC
7130, NGC 5135 and IC 3639). These galaxies, together to Mrk 477, were selected
from a bigger sample that comprises the 20 brightest Seyfert 2 nuclei, with the
goal to study the origin of the UV-optical-near IR featureless continuum in
Seyfert 2 nuclei. These four galaxies have bolometric luminosities, as computed
with the four IRAS bands, of 10^11 Lsol. They are close enough to be resolved
with HST the nuclear zone. This makes these Seyfert 2 galaxies benchmarks to
study the Starburst-AGN connection in more distant galaxies.
The data provide direct evidence of the existence of a central nuclear
starburst that dominates the UV light, and that seem to be responsible for the
origin of the so called featureless continuum. These starbursts are dusty and
compact. They have sizes (from less than 100 pc to a few hundred pc) much
smaller and closer to the nucleus than that seen in the prototype Seyfert 2
galaxy NGC 1068. The bolometric luminosity of these starbursts is similar to
the estimated bolometric luminosities of their obscured Seyfert 1 nuclei, and
thus they contribute in the same amount to the overall energetics of these
galaxies.Comment: to be published in ApJ 505, September issue. The figures are in a tar
files at: http://www.iaa.es/~rosa/Seyfert