2024/09/29 by Ahmed, O., Degenaar, N., Wijnands, R. +1
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · doi:10.48550/arxiv.2409.19649
XMMSL1 J171900.4-353217 is a very-faint X-ray transient that was discovered in 2010 March when it exhibited an outburst. We report on 7 observations, obtained with the X-Ray Telescope (XRT) aboard the Neil Gehrels \itSwift Observatory between 2010 May to October. By fitting a single absorbed power-law model to the XRT spectra, we infer power-law indices of Γ= 1.8-2.7 and an absorption column density of NH=(4.6-7.9)× 1022~cm-2. The inferred 0.5-10~keV luminosity fluctuated irregularly and peaked at LX≃ 1035-1036 ~\mathrmerg~s-1 for a distance of 4-12~kpc. Based on the evolution of the power-law index with varying luminosity, we propose that the source most likely is a transient neutron star low-mass X-ray binary located at several kpc. If true, it would be a good candidate to search for coherent millisecond pulsations when it enters a new accretion outburst.