A puzzling event during the X-ray emission of the binary system GX 1+4
Abstract
We report on a long X-ray observation of the slow-rotating binary pulsar GX 1+4. BeppoSAX observed, in the 0.1-200 keV energy range, an event in which the source flux dropped for almost a day, and then recovered. During this event only the high-energy emission was found to be pulsed and the pulsations were shifted in phase of ~0.2 . The spectrum during the event was well fitted by a Compton-reflection model. A broad iron line at ~6.55 keV was present outside of the event, where instead two narrow emission lines at ~6.47 keV and ~7.05 keV were detected. The pulse profile was highly variable as a function of both energy and time. We interpret this low-flux event as an occultation of the direct X-ray emission, due to the increase of a torus-like accretion disk; we then discuss similarities between this source and the recently discovered highly absorbed INTEGRAL sources.
Cite
@article{arxiv.astro-ph/0409626,
title = {A puzzling event during the X-ray emission of the binary system GX 1+4},
author = {Nanda Rea and Luigi Stella and Gian Luca Israel and Giorgio Matt and Silvia Zane and Alberto Segreto and Tim Oosterbroek},
journal= {arXiv preprint arXiv:astro-ph/0409626},
year = {2015}
}
Comments
accepted for publication in Advances in Space Research