Absorption and scattering properties in polarized bright soft X-ray selected ROSAT AGN

Abstract

We have surveyed the optical linear polarimetric properties of 65 soft X-ray selected ROSAT Active Galactic Nuclei (AGN). Most of these sources show low polarization (<1%) and no optical reddening. This is in agreement with the X-ray results suggesting a direct view on the center. However, two of our AGN show polarization as high as 7--8% and high reddening. This optical reddening suggests a high column of dusty gas, but why does this gas not absorb the soft X-rays? We suggest that the dusty gas is actually ionized. There is evidence for these 'warm' absorbers from X-ray absorption features seen in ROSAT and ASCA spectra.

3 pages, including 3 pages, to appear in the proc. of "Highlights in X-ray Astronomy" (Garching, June 1998), B Aschenbach et al. (eds); MPE preprint 448, also available at: http://www.xray.mpe.mpg.de/~dgrupe/research/unrefereed.html