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arXiv · 2308.12498

Quiet, but not silent: Uncovering quiescent state properties of two transient High Mass X-ray binaries

Gayathri Raman·Varun·Pragati Pradhan·Jamie Kennea
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Abstract

We present the first set of broadband spectral and timing studies of two transient X-ray pulsars, MXB 0656-072 and MAXI J1409-619 using NuSTAR observations conducted during quiescence. Despite being captured at one of their lowest luminosity states, both these targets show signs of ongoing low-level accretion. Results from the time-averaged spectral analysis indicate for the first time, the presence of a strong soft power law component along with thermal emission from the neutron star hot spots. For both targets, the quiescent thermal X-ray emission is consistent with the deep crustal heating model. In MXB 0656-072, we do not detect any pulsations or indications of a cyclotron line during quiescence. However, in MAXI J1409-619 we detect strong pulsations at 502 s with a pulsed fraction of $\sim$66%, which adds this pulsar to the list of a handful of quiescent-state pulsating systems.

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Gayathri Raman, Varun, Pragati Pradhan, Jamie Kennea. 2023-08-24. Quiet, but not silent: Uncovering quiescent state properties of two transient High Mass X-ray binaries. https://arxiv.org/abs/2308.12498

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