BL Lacertae Objects

This grant has contributed to one of the original goals of the NAS/LTSA program, the goal of junior faculty development. Below I briefly summarize the following major results on BL Lacertae Objects that we have obtained. An invited talk on BL Lac Objects at IAU 175 "Extragalactic Radio Sources" at Bologna Italy in October 1995 summarized some of these results. A second invited talk in Oct 1998 at Green Bamk, WVA presented other BL Lac results at the conference entitled: "Highly Redshifted Radio Lines". We have used the EMSS sample to measure the X-ray luminosity function and cosmological evolution of BL Lacs. A new large sample of XBLs has been discovered.