The pre-outburst flare of the A 0535+26 August/September 2005 outburst
Caballero I, Santangelo A, Kretschmar P, Staubert R, Postnov K, Klochkov D, Camero-Arranz A, Finger MH, Kreykenbohm I, Pottschmidt K, Rothschild RE, Suchy S, Wilms J, Wilson CA (2008)
Publication Status: Published
Publication Type: Journal article
Publication year: 2008
Journal
Publisher: EDP SCIENCES S A
Book Volume: 480
Pages Range: L17-U1
Journal Issue: 2
DOI: 10.1051/0004-6361:20079310
Abstract
We study the spectral and temporal behavior of the High Mass X-ray Binary A 0535+26 during a "pre-outburst flare" which took place similar to 5d before the peak of a normal (type I) outburst in August/September 2005. We compare the studied behavior with that observed during the outburst.Methods. We analyse RXTE observations that monitored A 0535+26 during the outburst. We complete spectral and timing analyses of the data. We study the evolution of the pulse period, present energy-dependent pulse profiles both at the initial pre-outburst flare and close to outburst maximum, and measure how the cyclotron resonance-scattering feature (hereafter CRSF) evolves.Results. We present three main results: a constant period P = 103.3960(5) s is measured until periastron passage, followed by a spin-up with a decreasing period derivative of. P = (-1.69 +/- 0.04) x 10(-8) s s(-1) at MJD 53 618, and P remains constant again at the end of the main outburst. The spin-up provides evidence for the existence of an accretion disk during the normal outburst. We measure a CRSF energy of E-cyc similar to 50 keV during the pre-outburst flare, and E-cyc similar to 46 keV during the main outburst. The pulse shape, which varies significantly during both pre-outburst flare and main outburst, evolves strongly with photon energy.
Authors with CRIS profile
Involved external institutions
Eberhard Karls Universität Tübingen
Germany (DE)
University of Alabama in Huntsville (UAH)
United States (USA) (US)
University of California, San Diego
United States (USA) (US)
University of Maryland, Baltimore County
United States (USA) (US)
University of València / Universitat de València
Spain (ES)
European Space Astronomy Centre (ESAC)
Spain (ES)
Germany (DE)
University of Alabama in Huntsville (UAH)
United States (USA) (US)
University of California, San Diego
United States (USA) (US)
University of Maryland, Baltimore County
United States (USA) (US)
University of València / Universitat de València
Spain (ES)
European Space Astronomy Centre (ESAC)
Spain (ES)
How to cite
APA:
Caballero, I., Santangelo, A., Kretschmar, P., Staubert, R., Postnov, K., Klochkov, D.,... Wilson, C.A. (2008). The pre-outburst flare of the A 0535+26 August/September 2005 outburst. Astronomy & Astrophysics, 480(2), L17-U1. https://dx.doi.org/10.1051/0004-6361:20079310
MLA:
Caballero, I., et al. "The pre-outburst flare of the A 0535+26 August/September 2005 outburst." Astronomy & Astrophysics 480.2 (2008): L17-U1.
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