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X-ray spectral and timing properties of the 2001 superburst of 4U 1636-536

Erik Kuulkers·Jean in 't Zand·Jeroen Homan·Steve van Straaten·Diego Altamirano·Michiel van der Klis
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Abstract

Preliminary results are reported on the spectral and timing properties of the spectacular 2001 superburst of 4U 1636-536 as seen by the RXTE/PCA. The (broad-band) power-spectral and hardness properties during the superburst are compared to those just before and after the superburst. Not all of the superburst emission can be fitted by pure black-body radiation. We also gathered BeppoSAX/WFC and RXTE/ASM data, as well as other RXTE/PCA data, obtained days to months before and after the superburst to investigate the normal X-ray burst behavior around the time of the superburst. The first normal X-ray burst after the 2001 superburst was detected 23 days later. During inspection of all the RXTE/ASM data we found a third superburst. This superburst took place on June 26, 1999, which is ~2.9 yrs after the 1996 superburst and ~1.75 yrs before the 2001 superburst. The above findings are the strongest constraints observed so far on the duration of the cessation of normal X-ray bursts after a superburst and the superburst recurrence times.

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Erik Kuulkers, Jean in 't Zand, Jeroen Homan, Steve van Straaten, Diego Altamirano, Michiel van der Klis. 2004-02-03. X-ray spectral and timing properties of the 2001 superburst of 4U 1636-536. https://doi.org/10.1063/1.1781037

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