Swift monitoring of the new accreting millisecond X-ray pulsar IGR J17511-3057 in outburst
Abstract
Context. 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.
Aims: To study the evolution of the source X-ray flux and spectral properties during the outburst, we requested a Swift monitoring of IGR J17511-3057.
Methods: In this paper we report on the results of the first two weeks of monitoring the source.
Results: The persistent emission of IGR J17511-3057 during the outburst is modelled well with an absorbed blackbody (kT ~ 0.9 keV) and a power-law component (Γ~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 theoretically expected recurrence time of the bursts according to the helium burst hypothesis is 0.2-0.9 days, in agreement with the observations.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- January 2010
- DOI:
- 10.1051/0004-6361/200913517
- arXiv:
- arXiv:0912.0127
- Bibcode:
- 2010A&A...509L...3B
- Keywords:
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- X-rays: binaries;
- pulsars: individual: IGR J17511-3057;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in A&