Confirmation of the spin period and coordinates of SXP523 with XMM-Newton
ATel #4719; R. Sturm, F. Haberl, M. Freyberg (all Max-Planck-Institut fur extraterrestrische Physik), M. Coe (Univ. of Southampton), A. Udalski (Warsaw University Observatory)
on 9 Jan 2013; 17:05 UT
Credential Certification: Richard Sturm (rsturm@mpe.mpg.de)
Subjects: X-ray, Neutron Star, Transient, Pulsar
The recently discovered 522.5 s pulsar transient in the SMC - Suzaku J0102-7204 - (ATel #4628),
was identified with the Be/X-ray binary XMM J010247.4-720449 (ATel #3761, ATel #4648).
With new XMM-Newton data we can confirm both,
pulsation period of Suzaku J0102-7204 and
the identification with the Be/X-ray binary 2XMM J010247.4-720449.
Within an XMM-Newton calibration observation (ObsID 0412981701) of the supernova remnant 1E 0102.2-7219
performed from 2012-12-06 16:05 to 2012-12-07 11:32,
SXP523 was in outburst 38 days after the Suzaku detection.
The source is covered by three exposures of each EPIC-MOS camera.
The position of the XMM-Newton source is 01:02:47.42 -72:04:50.8 (J2000) with an uncertainty of 0.62".
Using the spectral model as described in ATel #3761,
we derive a photon index of Γ=0.93±0.13,
an absorbing column density in the SMC of NH = (2.1±1.7) × 1021 cm-2,
and a measured flux in the (0.2-10.0) keV band of (3.2±0.2) × 10-13 erg cm-2 s-1.
For a distance of 60 kpc, this corresponds to an unabsorbed luminosity of 1.5 × 1035 erg s-1.
With XMM-Newton, we derive coherent pulsations at (521.42±0.21) s, seen in both EPIC-MOS cameras.
All uncertainties are given for 1σ confidence.
The combined OGLE II, III, and IV data sets were investigated for possible periodic behaviour indicative of binarity.
For the first 11 years (JD 2450628 - 2454925) the source was in a quiescent mode (I~16.2 mag) and amenable to an effective Lomb-Scargle search.
Significant power is seen around a period of 490 days which appears to be unrelated to the annual sampling.
After that epoch the source underwent two major optical outbursts of order ~0.5 mag, each of which lasted 1-2 years.
The most recent data indicate a return to quiescent levels.
