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Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE
Abstract:
We present a systematic coherent X-ray pulsation search in eleven low mass
X-ray binaries (LMXBs). We select a relatively broad variety of LMXBs,
including persistent and transient sources and spanning orbital periods between
0.3 and 17 hours. We use about 3.6 Ms of data collected by the Rossi X-Ray
Timing Explorer (RXTE) and XMM-Newton and apply a semi-coherent search strategy
to look for weak and persistent pulses in a wide spin frequency range. We find
no evidence for X-ray pulsations in these systems and consequently set upper
limits on the pulsed sinusoidal semi-amplitude between 0.14% and 0.78% for ten
outbursting/persistent LMXBs and 2.9% for a quiescent system. These results
suggest that weak pulsations might not form in (most) non-pulsating LMXBs.
