We investigate the cyclotron resonant scattering features (CRSFs) of the accreting X-ray pulsar Cen X-3 and significantly detect the 29 keV cyclotron line features in the hard X-ray averaged spectroscopy studies based on the recent Insight-HXMT observations in 2022, when Cen X-3 has X-ray luminosity LX>∼5×1037 erg\ s−1 in the bands of 2 -- 60 keV. We do not find a harmonic line in the average spectra based on different continuum models. We showed that the CRSF energies have no correlation with time or luminosity in the average spectra. In addition, by performing a pulse phase-dependent spectral analysis, we revealed the fundamental line with the centroid energy ranging from 25 to 29 keV with a high significance over the spin phases. The evolution of the cyclotron line centroid energies over pulse phase is similar to the shape of pulse profiles, illustrating a positive correlation between the energy of CRSFs and the pulse phase flux.
@article{arxiv.2410.20520,
title = {Studying the variations of the cyclotron line in Cen X-3 using Insight-HXMT},
author = {Qi Liu and Wei Wang and Wen Yang and Xiao Chen and Hanji Wu},
journal= {arXiv preprint arXiv:2410.20520},
year = {2024}
}