Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst
astro-ph.HE
/ Authors
Yue Zhang, Mingyu Ge, Liming Song, Shuangnan Zhang, Jinlu Qu, Shu Zhang, Victor Doroshenko, Lian Tao, Long Ji, Can Güngör
and 100 more authors
Andrea Santangelo, Changsheng Shi, Zhi Chang, Gang Chen, Li Chen, Tianxiang Chen, Yong Chen, Yibao Chen, Wei Cui, Weiwei Cui, Jingkang Deng, Yongwei Dong, Yuanyuan Du, Minxue Fu, Guanhua Gao, He Gao, Min Gao, Yudong Gu, Ju Guan, Chengcheng Guo, Dawei Han, Wei Hu, Yue Huang, Jia Huo
/ Abstract
The recently discovered neutron star transient Swift J0243.6+6124 has been monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT). Based on the obtained data, we investigate the broadband spectrum of the source throughout the outburst. We estimate the broadband flux of the source and search for possible cyclotron line in the broadband spectrum. No evidence of line-like features is, however, found up to $\rm 150~keV$. In the absence of any cyclotron line in its energy spectrum, we estimate the magnetic field of the source based on the observed spin evolution of the neutron star by applying two accretion torque models. In both cases, we get consistent results with $B\rm \sim 10^{13}~G$, $D\rm \sim 6~kpc$ and peak luminosity of $\rm >10^{39}~erg~s^{-1}$ which makes the source the first Galactic ultraluminous X-ray source hosting a neutron star.