Search Publications

The structure of Algol's corona: a consistent scenario for the X-ray and radio emission
Bibcode: 2000A&A...362..628F

Schmitt, J. H. M. M.; Micela, G.; Favata, F. +2 more

We present a systematic analysis of the four known large X-ray flares detected to date on the eclipsing binary system Algol, using an approach based on hydrodynamic simulations of decaying flaring loops including sustained heating. This method yields, for the large BeppoSAX Algol flare of Aug. 1997 (where a geometrical estimate of the size of the …

2000 Astronomy and Astrophysics
Exosat 27
Photometric and spectroscopic studies of cool stars discovered in EXOSAT X-ray images. IV. The northern hemisphere sample
Bibcode: 2000A&A...364..205C

Tagliaferri, G.; de Medeiros, J. R.; Messina, S. +4 more

We present high-precision photometry, high- and medium-resolution spectroscopy for a sample of 32 stars likely to be the optical counterparts of X-ray sources serendipitously detected by the EXOSAT satellite. Using also recent results from the Hipparcos satellite, we infer spectral types, compute X-ray luminosities and Li abundances and investigat…

2000 Astronomy and Astrophysics
Exosat Hipparcos 17
No QPO time lags from Sco X-1 as seen with EXOSAT: a comparison with Cyg X-2
DOI: 10.48550/arXiv.astro-ph/9911287 Bibcode: 2000A&A...353..203D

Kuulkers, Erik; van der Klis, Michiel; Lamb, Frederick K. +2 more

We have measured the phase-delay and rms amplitude spectra of Cyg X-2 and Sco X-1. Using EXOSAT data from the normal branch of Cyg X-2 we confirm earlier (Ginga) results, showing that at an energy near 6 keV there is both a minimum in the quasi-periodic oscillations QPO rms amplitude spectrum and a 150deg phase jump in the QPO phase-del…

2000 Astronomy and Astrophysics
Exosat 9