Title:	New measurements of the cyclotron line energy in Cen X-3
Authors:	Tomar, Gunjan Pradhan, Pragati Paul, Biswajit
Keywords:	stars neutron – pulsars general –X-rays binaries – X-rays individual Cen X-3
Issue Date:	Jan-2021
Publisher:	Oxford University Press on behalf of the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2021, Vol.500, p 3454–3461
Abstract:	We report results from the analysis of data from two observations of the accreting binary X-ray pulsar Cen X-3 carried out with the broad-band X-ray observatories Suzaku and NuSTAR. The pulse profile is dominated by a broad single peak and show some energy dependence with two additional weak pulse peaks at energies below 15 and 25 keV, respectively. The broad-band X-ray spectrum for 0.8–60.0 keV for Suzaku and 3.0–60.0 keV for NuSTAR is fitted well with high-energy cut-off power-law model along with soft-excess, multiple iron emission lines and a cyclotron absorption. The cyclotron line energy is found to be 30.29+0.68 −0.61 and 29.22+0.28 −0.27 keV, respectively, in the Suzaku and NuSTAR spectra. We make a comparison of these two measurements with four previous measurements of Cyclotron Resonant Scattering Feature (CRSF) in Cen X-3 obtained with Ginga, BeppoSAX, and RXTE. We find no evidence for a dependence of the CRSF on uminosity. Except for one CRSF measurement with BeppoSAX , the remaining measurements are consistent with a CRSF energy in the range of 29.5–30.0 keV over a luminosity range of 1.1–5.4 × 1037 erg s−1 different from several other sources that show considerable CRSF variation in the same luminosity range.
Description:	Open Access.
URI:	http://hdl.handle.net/2289/7657
ISSN:	0035-8711 1365-2966 - (online)
Alternative Location:	https://academic.oup.com/mnras/article/500/3/3454/5974294 https://arxiv.org/abs/2011.05534
Copyright:	2021 The Author(s)
Appears in Collections:	Research Papers (A&A)

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