NuSTAR detection of a broad absorption line in IGR J06074+2205

NuSTAR detection of a broad absorption line in IGR J06074+2205
Mohammed Tobrej, Binay Rai, Manoj Ghising, Bikash Chandra Paul
arXiv:2404.14805v1 Announce Type: new
Abstract: We present the broadband X-ray study of the BeXRB pulsar IGR J06074+2205 using NuSTAR observations. The temporal and spectral characteristics of the source are investigated. We detect coherent X-ray pulsations of the source and determine the spin period evolution. Using the current spin period data of the source, we show that the source is spinning down at 0.0202(2); s; $day^{-1}$. The pulse profiles are found to evolve with energy and luminosity. Another interesting feature of the source is that the pulse profiles are dual peaked. The dual-peaked pulse profile is characterized by a decreasing secondary peak amplitude with increasing energy. We also observed a proportionate increase in the primary peak amplitude as the energy increases. The pulse fraction exhibits an overall increasing trend with the energy. The X-ray continuum of the source indicates the existence of a characteristic absorption feature with a centroid energy $sim 55$ keV, which may be interpreted as a cyclotron line. We estimate the corresponding magnetic field strength to be $sim4.74times10^{12}$ G. A peculiar `10 keV’ absorption feature is observed in the X-ray spectra of the second observation.The luminosity measurements predict that the source may be accreting in the sub-critical regime.arXiv:2404.14805v1 Announce Type: new
Abstract: We present the broadband X-ray study of the BeXRB pulsar IGR J06074+2205 using NuSTAR observations. The temporal and spectral characteristics of the source are investigated. We detect coherent X-ray pulsations of the source and determine the spin period evolution. Using the current spin period data of the source, we show that the source is spinning down at 0.0202(2); s; $day^{-1}$. The pulse profiles are found to evolve with energy and luminosity. Another interesting feature of the source is that the pulse profiles are dual peaked. The dual-peaked pulse profile is characterized by a decreasing secondary peak amplitude with increasing energy. We also observed a proportionate increase in the primary peak amplitude as the energy increases. The pulse fraction exhibits an overall increasing trend with the energy. The X-ray continuum of the source indicates the existence of a characteristic absorption feature with a centroid energy $sim 55$ keV, which may be interpreted as a cyclotron line. We estimate the corresponding magnetic field strength to be $sim4.74times10^{12}$ G. A peculiar `10 keV’ absorption feature is observed in the X-ray spectra of the second observation.The luminosity measurements predict that the source may be accreting in the sub-critical regime.