Magnetic field and radial velocity of the star #alpha#"2 CVn

We analyse spectra of the well-known bright CP2 star #alpha#"2 CVn in order to test the suitability of a new equipment for magnetic field observations and a computer program for the calculation of magnetic surface maps. The variation of the longitudinal magnetic field, derived from the elements H and Si II, which are distributed probably homogeneously on the stellar surface, can be represented by the superposition of a dipole with a quadrupole using the model of the oblique rotator. The corresponding magnetic field structure on the stellar surface is compared with the distributions of the chemical elements Ti, Cr, and Fe determined by several authors. A series of CCD coude spectra as well as some selected observational sets, obtained by other authors in the last decades, were used for the search for periods in radial velocities. The accuracy of the period derived for a single data set does not allow us to draw a conclusion on the existence of a phase shift between the data sets. (orig.)Available from TIB Hannover: RR 7310(99-18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The ROSAT Bright Survey. Pt. 2 Catalogue of all high-galactic latitude RASS sources with PSPC countrated CR > 0.2s"-"1

We present a summary of an identification program of the more than 2000 X-ray sources detected during the ROSAT All-Sky Survey (Voges et al. 1999) at high galactic latitude, vertical stroke b vertical stroke >30 , with countrate above 0.2 s"-"1. This program, termed the ROSAT Bright Survey RBS, is to more than 99.5% complete. A sub-sample of 931 sources with countrate above 0.2 s"-"1 in the hard spectral band between 0.5 and 2.0 keV is to 100% identified. The total survey area comprises 20391 deg"2 at a flux limit of 2.4 x 10"-"1 erg cm"-"2 s"-"1 in the 0.5-2.0 keV band. About 1500 sources of the complete sample could be identified by correlating the RBS with SIMBAD and the NED. The remaining #propor to#500 sources were identified by low-resolution optical spectroscopy and CCD imaging utilizing telescopes at La Silla, Calar Alto, Zelenchukskaya and Mauna Kea. Apart from completely untouched sources, catalogued clusters and galaxies without published redshift as well as catalogued galaxies with unusual high X-ray luminosity were included in the spectroscopic identification program. Details of the observations with an on-line presentation of the finding charts and the optical spectra will be published separately. Here we summarize our identifications in a table which contains optical and X-ray information for each source. As a result we present the most massive complete sample of X-ray selected AGNs with a total of 669 members and a well populated X-ray selected sample of 302 clusters of galaxies with redshifts up to 0.70. Three fields studied by us remain without optical counterpart (RBS0378, RBS1223, RBS1556). While the first is a possible X-ray transient, the two latter are isolated neutron star candidates (Motch et al. 1999, Schwope et al. 1999). (orig.)Also published in Astronomische Nachrichten v. 321(1), 2000Available from TIB Hannover: RR 7310(2000-03) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman