Title:	XMM-Newton View of Pulsating Iron Fluorescent Emission from Centaurus X-3
Authors:	Roy, Kinjal Manikantan, Hemanth Paul, Biswajit
Issue Date:	1-Oct-2025
Publisher:	IOP Publishing Ltd
Citation:	The Astrophysical Journal, 2025, Vol. 991, p162
Abstract:	Centaurus X–3 (Cen X–3) is a bright, high-mass X-ray binary pulsar. We present a pulse phase–resolved X-ray spectral analysis of data from an archival XMM-Newton observation of Cen X–3 taken during the high state of the source. The observation was entirely in the out-of-eclipse part of the binary orbit. We study the pulse phase variability of the three Kα fluorescent emission lines from near-neutral, helium-like, and hydrogen-like iron, along with the iron Kβ emission line. All four lines show clear modulation with the pulse phase of the neutron star (NS), and modulation is found to be higher for the lines from highly ionised iron compared to the neutral lines. Structures within the light travel distance corresponding to the pulse period of the NS are likely responsible for the pulse phase modulation of the emission lines. We have also investigated the orbital phase dependence of the pulse phase variability in the iron lines by dividing the data into four segments at different orbital phases of Cen X–3. The pulse phase modulation behavior of the four lines is quite identical at different orbital phases of Cen X–3, indicating the pulsed iron emission region is persistent in nature and probably phase aligned with respect to the observer. The accretion stream intercepting the line of sight can probably produce the observed phase dependence of the iron fluorescence emission lines.
Description:	Open Access
URI:	http://hdl.handle.net/2289/8601
Alternative Location:	https://arxiv.org/abs/2509.25036 https://ui.adsabs.harvard.edu/abs/2025ApJ...991..162R/abstract https://inspirehep.net/literature/2974751 https://doi.org/10.3847/1538-4357/adf8e6
Copyright:	2025 The Author(s)
Appears in Collections:	Research Papers (A&A)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.