[AIT logo]

Institut für Astronomie und Astrophysik

Abteilung Astronomie

Sand 1, D-72076 Tübingen, Germany
[Uni logo]

Hinweis: Einige Seiten auf astro.uni-tuebingen.de können veraltet sein und werden nicht mehr aktualisiert.
Note: Some webpages at astro.uni-tuebingen.de may be outdated and will no longer be updated.

Preprint 14a/99

Monitoring the Short-Term Variability of Cyg X-1

Katja Pottschmidt (1), Jörn Wilms (1), Rüdiger Staubert (1), Michael A. Nowak (2), James B. Dove (3;4), William A. Heindl (5), and David M. Smith (6)

(1) Institut für Astronomie und Astrophysik, Astronomie, Universität Tübingen, Waldhäuser Str. 64, D-72076 Tübingen, Germany
(2) JILA, University of Colorado, Boulder, CO 80309-440, USA
(3) CASA, University of Colorado, Boulder, CO 80309-389, USA
(4) Dept. of Physics, Metropolitan State College of Denver, Denver, CO 80217-3362, USA
(5) University of California San Diego, La Jolla, CA 92093, USA
(6) SSL, University of California Berkeley, Berkeley, CA 94720, USA

To appear in: ESO Workshop on Black Holes, eds. L. Kaper et al., Springer

Abstract. We present first results from an RXTE monitoring campaign of the black hole candidate Cygnus X-1 in 1999. The spectral and temporal properties of this hard state black hole show considerable variability, even though the state does not change. We find that a shortening of the time lags is accompanied by a hardening of the X-ray spectrum, as well as by an increase of the characteristic "shot time scale". We briefly discuss possible physical/geometrical reasons for this variability of the hard state properties.

Key words: -

Paper (33k gzip'ed Postscript including figures)

[Home Page] [Preprints 1999] [Quick Reference] [Feedback]

Jürgen Barnstedt | Impressum
Last modified 14 Nov 2002
[Valid HTML 4.0!]