Host Environments of BL Lac Objects
Session 4 -- AGNs
Display presentation, Monday, 9:20-6:30, Pauley Room

[4.10] Host Environments of BL Lac Objects

Ronald Wurtz (CASA, University of Colorado), John T. Stocke (CASA, University of Colorado)

We present the fitted profiles for the host galaxies of over 40 BL Lac objects of known redshift (z \$\sim\$ 0.05--0.64). These objects make up the complete sample of X-ray selected BL Lac objects (Morris et al. 1991) from the the Einstein Medium Sensitivity Survey, and a subset of the complete sample of radio-selected BL Lacs from the 1 Jansky survey (Stickel, et al. 1991).

We find that generally these hosts are consistent with the host galaxies of Fanaroff-Riley Type I radio galaxies as well as Brightest Cluster Galaxies, but that a few host galaxies are clearly unusual and may be signs of a dissimilar sub-population of ``interesting objects''.

We also present galaxy clustering parameters for the fields around BL Lac objects. Preliminary indications are that, taken as a whole, these objects appear in regions of galaxy excess and thus their environments are similar to those of Fanaroff-Riley Type I radio galaxies.