RXTE monitoring of Centaurus A

Abstract

We report on the analysis from ~110 ks of X-ray observations of Centaurus A carried out with the Proportional Counter Array (PCA) and the High Energy X-ray Timing Experiment (HEXTE) instruments on Rossi X-ray Timing Explorer (RXTE) during three monitoring campaigns over the last 4 years (10 ks in 1996, 74 ks in 1998, and 25 ks in 2000). The joint PCA/HEXTE X-ray spectrum can be well described by a heavily absorbed power law with photon index 1.8 and a narrow iron line due to fluorescence of cold matter. The measured column depth decreased by about 30% between 1996 and 2000, while the detected 2-10 keV continuum flux remained constant between 1996 and 1998, but increased by 60% in 2000. Since in all three observations the iron line flux did not vary, a corresponding decrease in equivalent width was noted. No appreciable evidence for a reflection continuum in the spectrum was detected. We present the interpretation of the iron line strength through Monte Carlo computations of various geometries. No significant temporal variability was found in Cen A at time scales from days to tens of minutes.

arXiv comment7 pages, 4 figures. Accepted for publication in A&A

References in corpus (12)

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• X-ray and soft gamma-ray spectra of Broad-Line Radio Galaxies
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• BeppoSAX Observations of the Radio Galaxy Centaurus A

Cited by in corpus (10)

• Chandra and XMM-Newton Observations of the Nucleus of Centaurus A
• Rapid and multi-band variability of the TeV-bright active nucleus of the galaxy IC 310
• The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
• The Hard X-ray Emission of Cen A
• The variable and non-variable X-ray absorbers in Compton-thin type-II Active Galactic Nuclei
• Spectral Survey of X-Ray Bright Active Galactic Nuclei from the Rossi X-ray Timing Explorer
• INTEGRAL observations of AGN in the Galactic Plane
• INTEGRAL and RXTE Observations of Centaurus A
• BeppoSAX Observations of Centaurus A: the Hard Continuum and the Iron Line Feature
• Hard X-ray/Soft gamma-ray experiments and missions: overview and prospects