7 papers
Late-type field stars in the RASS at high galactic latitude
F. -J. Zickgraf, J. Krautter, S. Frink +4
We present results of an investigation on a high-galactic latitude sample of late-type field stars selected from the ROSAT All-Sky Survey (RASS). The sample comprises about 200 G,…
Identification of a complete sample of northern ROSAT All-sky survey X-ray sources. VII. The AGN subsample
I. Appenzeller, F. -J. Zickgraf, J. Krautter +1
In order to derive statistical properties of a complete X-ray selected sample of AGN we used the classification spectra of the RASS Selected Areas-North survey to study the luminos…
The late-type stellar component in the ROSAT All-Sky Survey at high galactic latitude
F. -J. Zickgraf, J. M. Alcala, E. Covino +4
We investigated the properties of the late-type stellar component in the RASS at high-galactic latitude |b| based on an optically identified sample of ROSAT All-Sky Survey (RASS) X…
The connection with B[e] stars
Franz-Josef Zickgraf
The characteristics of the various types of B[e] stars are discussed and compared with those of classical Be stars. Both groups of stars are characterized by the presence of emissi…
Identification of a complete sample of northern ROSAT All-Sky Survey X-ray sources. IV. Statistical analysis
J. Krautter, F. -J. Zickgraf, I. Appenzeller +8
We present the statistical evaluation of a count rate and area limited complete sample of the ROSAT All-Sky Survey (RASS) comprising 674 sources. The RASS sources are located in si…
A New Cataclysmic Variable RX J0757.0+6306: Candidate for the Shortest Period Intermediate Polar
G. H. Tovmassian, J. Greiner, P. Kroll +8
A new cataclysmic variable is identified as the optical counterpart of the faint and hard X-ray source RX J0757.0+6306 discovered during the ROSAT all-sky survey. Strong double-pea…