258 citations · 2k across the 53 of their papers we have counts for
8 papers · 1 filter
The large-scale diffuse X-ray emission surrounding quasars: an investigation using the scaling-index method
K. A. Williams, W. Brinkmann, G. Wiedenmann
The large-scale (~ 20') diffuse x-ray background surrounding a sample of quasars observed during ROSAT PSPC pointed observations is studied using a new source-detection algorithm,…
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…
X-ray properties of the Parkes sample of flat-spectrum radio sources: dust in radio-loud quasars?
J. Siebert, W. Brinkmann, M. J. Drinkwater +4
We investigate the X-ray properties of the Parkes sample of flat-spectrum radio sources using data from the ROSAT All-Sky Survey and archival pointed PSPC observations. In total, 1…
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…