Thermonuclear X-ray burst of MXB 1658-298 with NuSTAR

Abstract

MXB 1658-298 is a transient Low-Mass X-ray Binary (LMXB), which shows eclipses, dips and bursts in its light curve. This source has undergone three active periods separated by long quiescent phases. The latest phase of enhanced X-ray emission was observed during 2015–2016. We have analysed broadband data from Swift/XRT and NuSTAR observations carried out in 2015. During NuSTAR observation, one thermonuclear X-ray burst took place. The X-ray emission during the burst was brighter by a factor of ∼200, compared to the pre-burst emission. This work focuses on the spectral analysis of MXB 1658-298 during the persistent and the burst phases using NuSTAR observation of 2015. We have also determined the temperature and radius evolution during the burst using the time-resolved spectroscopy. The burst phase shows mild Photospheric Radius Expansion (PRE).