11 papers
Optical and X-ray monitoring of the NLS1 galaxy Ark 564
I. E. Papadakis, W. Brinkmann, H. Negoro +3
The Narrow-line Seyfert galaxy Ark 564 was monitored between June 04, 2000 and June 24, 2000 from Skinakas Observatory. The B,V,R and I band light curves show night to night variat…
ROSAT HRI monitoring of X-ray variability in the NLS1 galaxy PKS 0558-504
M. Gliozzi, Th. Boller, W. Brinkmann +1
We present the results of ROSAT High Resolution Imager (HRI) observations and the survey data of the radio-loud Narrow-Line Seyfert 1 galaxy (NLS1) PKS 0558--504. We find strong an…
ROSAT HRI observations of radio-loud AGN
M. Gliozzi, W. Brinkmann, S. A. Laurent-Muehleisen +2
We present the results of three ROSAT HRI observations of AGN expected to reside in clusters of galaxies. Although the exposures were truncated by the premature end of the ROSAT mi…
An ASCA observation of the radio-loud narrow-line Seyfert 1 galaxy RGB J0044+193
J. Siebert, K. M. Leighly, S. A. Laurent-Muehleisen +3
We present the results of an ASCA observation of the radio-loud NLS1 galaxy RGB J0044+193. The X-ray data are complemented by radio observations and a new optical spectrum for this…
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…