A Deep Pulse Search in 11 Low Mass X-Ray Binaries

作者：Patruno A^*; Wette K; Messenger C

来源：Astrophysical Journal, 2018, 859(2): 112.

DOI：10.3847/1538-4357/aabf89

• binaries: general
• stars: neutron
• stars: rotation
• X-rays: binaries
• X-rays: stars

We present a systematic coherent X-ray pulsation search in 11 low mass X-ray binaries (LMXBs). We select a relatively broad variety of LMXBs, including persistent and transient sources, spanning orbital periods between 0.3 and 17 hr. We use about 3.6 Ms of data collected by the Rossi X-Ray Timing Explorer 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 below 1.6% for ten outbursting/persistent LMXBs and 6% for a quiescent system; the upper limits are further refined, by searching a narrower parameter space around the outliers, down to 0.14%-0.78% and 2.9%, respectively. These results suggest that weak pulsations might not form in (most) non pulsating LMXBs.

• 出版日期2018-6-1