Revisiting SW J2000.6+3210: a persistent Be X-ray pulsar?

Abstract

We present a detailed timing and spectral analysis of the Be X-ray binary SWJ2000.6+3210 discovered by the BAT Galactic plane survey. Two Suzaku observations of the source made at six months interval, reveal pulsations at ~ 890s for both observations with a much weaker pulse fraction in the second one. Pulsations are clearly seen in the energy band of 0.3-10 keV of XIS for both observations and at high energies up to 40 keV for the second observation. The broad band X-ray spectrum is consistent with a powerlaw and high energy cutoff model along with a hot blackbody component. No change in spectral parameters is detected between the observations. We have also analyzed several short observations of the source with Swift/XRT and detected only a few percent variation in flux around a mean value of 3:5 *10^{-11} erg cm^{-2} s^{-1}. The results indicates that SWJ2000.6+3210 is a member of persistent Be X-ray binaries which have the same broad characteristics as this source.