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arXiv · 0912.0127

Swift monitoring of the new accreting millisecond X-ray pulsar IGRJ17511-3057 in outburst

E. Bozzo·C. Ferrigno·M. Falanga·S. Campana·J. A. Kennea·A. Papitto
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Abstract

A new accreting millisecond X-ray pulsar, IGR J17511-3057, was discovered in outburst on 2009 September 12 during the INTEGRAL Galactic bulge monitoring programme. To study the evolution of the source X-ray flux and spectral properties during the outburst, we requested a Swift monitoring of IGRJ17511-3057. In this paper we report on the results of the first two weeks of monitoring the source. The persistent emission of IGR J17511-3057 during the outburst is modeled well with an absorbed blackbody (kT~0.9 keV) and a power-law component (photon index~1-2), similar to what has been observed from other previously known millisecond pulsars. Swift also detected three type-I Xray bursts from this source. By assuming that the peak luminosity of these bursts is equal to the Eddington value for a pure helium type-I X-ray burst, we derived an upper limit to the source distance of ~10 kpc. The theoretical, expected recurrence time of the bursts according to the helium burst hypothesis is 0.2-0.9 days, in agreement with the observations.

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E. Bozzo, C. Ferrigno, M. Falanga, S. Campana, J. A. Kennea, A. Papitto. 2009-12-01. Swift monitoring of the new accreting millisecond X-ray pulsar IGRJ17511-3057 in outburst. https://doi.org/10.1051/0004-6361/200913517

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