Orbital Modulation and Long Term Spin-up Rate of SWIFT J1626.6-5156
ATel #2250; A. Baykal (METU), S. C. Inam (Baskent), E. Gogus (Sabanci), T. M. Belloni (INAF)
on 21 Oct 2009; 15:00 UT
Credential Certification: Sitki Cagdas Inam (inam@baskent.edu.tr)
Subjects: X-ray, Binary, Neutron Star, Transient, Pulsar
We report on the long-term pulse period history of the ~15.35s X-ray pulsar SWIFT J1626.6-5156 obtained from pulse timing analysis of RXTE-PCA observations between MJD ~53724 and MJD ~54379. A preliminary circular orbit fit to the pulse period history between MJD ~53924 (200 days after the first observation) and MJD ~54379 reveals an orbital period of ~132.9 days.
From this preliminary fit to the pulse period history, we obtain an (a/c)sini value of ~405sec which corresponds to a mass function value of ~4.2 Solar mass. The source is also found to have a secular spin-up between MJD ~53924 and MJD ~54379 with a rate of ~1.37x10^{-12} Hz/sec.
Work on pulse arrival time history to obtain a more accurate orbital model of the source is in progress.
