利用HXMT研究X射线双星能谱特征与光度的演化关系

X射线双星是慧眼卫星HXMT的核心科学目标之一。X射线双星高能辐射反映了致密天体剧烈活动的物理特征，是探测宇宙强引力场、致密物质、超强磁场环境的探针。HXMT可以精确测量X射线双星（黑洞和中子星系统）宽波段X射线能谱（1-250 keV）,同时获得热辐射和非热辐射的能谱，并有助于搜寻铁吸收线和回旋吸收线的谱线特征。本项目将通过能谱精细分析来研究黑洞和中子星X射线双星的吸积盘内半径与光度的关系，搜寻铁吸收线并研究其与光度的关系，来寻找X射线双星中物质外流的证据。研究中子星双星的回旋吸收线特征参数与光度的关系，研究中子星表面磁场及吸积柱的物理特征和辐射机制。

X-ray binaries are the core science program of the HXMT observations. The high energy emissions in X-ray binaries reflect the activity near compact objects, probing the physics in the ultra-strong gravity, strong magnetic field and ultra-high density. HXMT can measure the broad X-ray spectra from 1- 250 keV in X-ray binaries including black holes and neutron stars, then can obtain both the thermal and non-thermal spectra, which will help to search for the iron absorption line and cyclotron absorption features. In this program, we will analyze the spectra of X-ray binaries to study the relations between the inner radius of the accretion disk and X-ray luminosity, and search for the iron absorption line features and study variations of iron absorption line with luminosities, so that we can find the evidence of outflows in X-ray binaries. In addition, we will study the variation of the cyclotron absorption line features with luminosities in neutron star X-ray binaries, which will probe the strong magnetic field and geometry of accretion column, radiation mechanism near the surface of neutron stars.