Integral and RXTE observations of Centaurus A

Rothschild RE, Wilms J, Tomsick JA, Staubert R, Benlloch-Garcia S, Collmar W, Madejski GM, Deluit S, Khandrika H (2006)

Publication Status: Published

Publication Type: Journal article

Publication year: 2006

Journal

Astrophysical Journal American Astronomical Society

Publisher: IOP PUBLISHING LTD

Book Volume: 641

Pages Range: 801-821

Journal Issue: 2

Abstract

INTEGRAL and RXTE performed three simultaneous observations of the nearby radio galaxy Centaurus A in 2003 March, 2004 January, and 2004 February with the goals of investigating the geometry and emission processes via the spectral/temporal variability of the X-ray/low-energy gamma-ray flux, and intercalibration of the INTEGRAL instruments with respect to those on RXTE. Cen A was detected by both sets of instruments from 3 to 240 keV. When combined with earlier archival RXTE results, we find the power-law continuum flux and the line-of-sight column depth varied independently by 60% between 2000 January and 2003 March. Including the three archival RXTE observations, the iron-line flux was essentially unchanging, and from this we conclude that the iron-line-emitting material is distant from the site of the continuum emission, and that the origin of the iron-line flux is still an open question. Taking X-ray spectral measurements from satellite missions since 1970 into account, we discover a variability in the column depth between 1.0 x 10(23) and 1.5 x 10(23) cm(-2) separated by approximately 20 yr, and suggest that variations in the edge of a warped accretion disk viewed nearly edge-on might be the cause. The INTEGRAL OSA 4.2 calibration of JEM-X, ISGRI, and SPI yields power-law indices consistent with the RXTE PCA and HEXTE values, but the indices derived from ISGRI alone are about 0.2 greater. Significant systematics are the limiting factor for INTEGRAL spectral parameter determination.

Authors with CRIS profile

Jörn Wilms Professur für Astronomie und Astrophysik

Involved external institutions

Eberhard Karls Universität Tübingen DE Germany (DE) Stanford University US United States (USA) (US) University of California, San Diego (UC San Diego, UCSD) US United States (USA) (US) University of California, Berkeley (UC Berkeley) US United States (USA) (US) Data Centre for Astrophysics ISDC CH Switzerland (CH) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics DE Germany (DE)

How to cite

APA:

Rothschild, R.E., Wilms, J., Tomsick, J.A., Staubert, R., Benlloch-Garcia, S., Collmar, W.,... Khandrika, H. (2006). Integral and RXTE observations of Centaurus A. Astrophysical Journal, 641(2), 801-821.

MLA:

Rothschild, Richard E., et al. "Integral and RXTE observations of Centaurus A." Astrophysical Journal 641.2 (2006): 801-821.

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