Timing an Accreting Millisecond Pulsar: Measuring the Accretion Torque in IGR J00291+5934
Abstract
We performed a timing analysis of the fastest accreting millisecond pulsar IGR J00291+5934 using RXTE data taken during the outburst of 2004 December. We corrected the arrival times of all the events for the orbital (Doppler) effects and performed a timing analysis of the resulting phase delays. In this way we are able to study, for the first time in this class of sources, the spin-up of a millisecond pulsar as a consequence of accretion torques during the X-ray outburst. The accretion torque gives us for the first time an independent estimate of the mass accretion rate onto the neutron star, which can be compared with the observed X-ray luminosity. We also report a revised value of the spin period of the pulsar.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2007
- DOI:
- 10.1086/510659
- arXiv:
- arXiv:astro-ph/0611222
- Bibcode:
- 2007ApJ...657..961B
- Keywords:
-
- Stars: Pulsars: General;
- Stars: Pulsars: Individual: Alphanumeric: IGR J00291+5934;
- Stars: Magnetic Fields;
- Stars: Neutron;
- X-Rays: Binaries;
- Astrophysics
- E-Print:
- 7 pages including 1 figure. Accepted for publication by ApJ