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Corona(e) of AR Lacertae. II. The Spatial Structure

White, N. E.; Singh, K. P.; Siarkowski, M. +2 more

The X-ray light curves in the 0.4-1.5 keV and 2-7 keV bands of the RS CVn binary AR Lacertae observed on 1993 June 1-3 over one full orbital cycle with the ASCA satellite have been used to map the spatial structure of AR Lac's coronae. We find that both stars are X-ray active, that the corona of the K-type secondary star appears to be hotter than …

Anticorrelation of Variability Amplitude with X-Ray Luminosity for Active Galactic Nuclei

Abramowicz, Marek A.; Bao, Gang

The bright-spot model for the short-term X-ray variability of active galactic nuclei predicts that, statistically, sources with larger luminosities should have smaller variability amplitudes. This quantitatively agrees with the analysis of the observational data from 12 high-quality EXOSAT long looks performed by Lawrence & Papadakis.

The Soft and Medium-Energy X-Ray Variability of NGC 5548: A Reanalysis of EXOSAT Observations

Tagliaferri, G.; Stella, L.; Treves, A. +2 more

We present a detailed cross-correlation (CCF) and power spectrum reanalysis of the X-ray light curves of the bright Seyfert 1 galaxy NGC 5548 obtained with EXOSAT. The 0.05-2 keV and 1-4 keV light curves are cross-correlated with the 1-9 keV and 4-9 keV light curves, respectively. We discuss how spurious time lags can be introduced by systematic e…