2024/01/04 by A. B. Mason, A. J. Norton, Mason, A. B. +7
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astrophysical Phenomena and Observations #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Pulsars and Gravitational Waves Research #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2401.02468
openalex publication_date 2024/01/04 · openalex created_date 2024/01/13 · openalex updated_date 2026/07/28
We aim to investigate the nature of time-variable X-ray sources detected in the \it XMM-Newton serendipitous survey. The X-ray light curves of objects in the \it XMM-Newton serendipitous survey were searched for variability and coincident serendipitous sources observed by \it Chandra were also investigated. Subsequent infrared spectroscopy of the counterparts to the X-ray objects that were identified using UKIDSS was carried out using \it ISAAC on the VLT. We found that the object 4XMM~J182531.5--144036 detected in the \it XMM-Newton serendipitous survey in April 2008 was also detected by \it Chandra as CXOU~J182531.4--144036 in July 2004. Both observations reveal a hard X-ray source displaying a coherent X-ray pulsation at a period of 781~s. The source position is coincident with a K=14 mag infrared object whose spectrum exhibits strong HeI and Brγ emission lines and an infrared excess above that of early B-type dwarf or giant stars. We conclude that 4XMM~J182531.5--144036 is a Be/X-ray binary pulsar exhibiting persistent X-ray emission and is likely in a long period, low eccentricity orbit, similar to X Per.