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arXiv · 1705.05205

Post-flare Formation of the Accretion Stream and a Dip in Pulse Profiles of LMC X-4

Aru Beri·Biswajit Paul
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Abstract

We report here a pulse profile evolution study of an accreting X-ray pulsar LMC X-4 during and after the large X-ray flares using data from the two observatories XMM-Newton and RXTE. During the flares, the pulse profiles were found to have a significant phase offset in the range of 0.2-0.5 compared to the pulse profiles immediately before or after the flare. Investigating the pulse profiles for about 10^5 seconds after the flares, it was found that it takes about 2000-4000 seconds for the modified accretion column to return to its normal structure and formation of an accretion stream that causes a dip in the pulse profile of LMC X-4. We have also carried out pulse phase resolved spectroscopy of LMC X-4 in narrow phase bins using data from EPIC-pn and spectroscopically confirmed the pulsating nature of the soft spectral component, having a pulse fraction and phase different from that of the power-law component.

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Aru Beri, Biswajit Paul. 2017-05-15. Post-flare Formation of the Accretion Stream and a Dip in Pulse Profiles of LMC X-4. https://doi.org/10.1016/j.newast.2017.05.001

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