5 papers · 1 filter
Four New BL Lac Surveys: Sampling New Populations
S. A. Laurent-Muehleisen, R. H. Becker, W. Brinkmann +5
The advent of large area deep radio and X-ray surveys is leading to the creation of many new BL Lac samples. In particular, the ROSAT All-Sky, Green Bank and FIRST surveys are prov…
The broad band X-ray spectra of intermediate BL Lac objects
J. Siebert, W. Brinkmann, S. A. Laurent-Muehleisen +1
We present recent X-ray observations of intermediate BL Lac objects (IBLs), i.e. BL Lacs which are located between high-energy and low-energy peaked BL Lac objects with respect to…
Recent X-ray observations of intermediate BL Lac objects
J. Siebert, W. Brinkmann, S. A. Laurent-Muehleisen
We present recent ROSAT, ASCA and SAX observations of intermediate BL Lac objects (IBLs), i.e. BL Lacs which are located between high-energy and low-energy peaked BL Lac objects wi…
Does the optical-to-X-ray energy distribution of quasars depend on optical luminosity?
W. Yuan, J. Siebert, W. Brinkmann
We report on a detailed analysis of the correlation between the optical-UV (Lo) and X-ray (Lx) luminosities of quasars by means of Monte Carlo simulations, using a realistic lumino…
ROSAT HRI observations of seven high redshift quasars
J. Siebert, W. Brinkmann
We present ROSAT HRI observations of six quasars with redshifts >3.4: PKS 0335-122, S4 0620+389, B1422+231, PKS 2215+02, Q 2239-386 and PC 2331+0216. We include the observation of…