X射线暴振荡的研究进展  

Research Progress of X-ray Burst Oscillation

作　　者：李清心 李兆升 LI Qing-xin;LI Zhao-sheng(Key Laboratory of Stars and Interstellar Medium,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学物理与光电工程学院,湘潭411105

出　　处：《天文学进展》2021年第2期187-210,共24页Progress In Astronomy

基　　金：国家自然科学基金(U1938107,11703021,U1838111,11873041);湖南省教育厅项目(18B059)。

摘　　要：X射线暴振荡是在小质量X射线双星的Ⅰ型X射线暴中探测到的周期性现象,振荡的周期与中子星的自转周期接近。近些年来,RXTE和NICER等高能探测器在30个小质量X射线双星中探测到了爆发振荡现象。X射线暴振荡对研究致密物质状态、中子星表面强引力和强磁场行为等都有着重要的意义。文章介绍了Ⅰ型X射线暴和爆发振荡的搜索方法、爆发振荡的观测结果、爆发振荡的热斑模型和表面模式振荡模型,未来,X射线暴振荡将用于测量中子星质量、半径和自转。X-ray burst oscillations are coherent signals which are detected in neutron star low-mass X-ray binaries during their type-Ⅰ X-ray bursts.The frequency of X-ray burst oscillation is close to the neutron star spin rate.In recent years,about 30 neutron star low-mass X-ray binaries have been detected X-ray burst oscillations from RXTE,Swift and NICER observations.They are important to probe the dense matter equation of state and the effects of strong gravity,to study the high magnetic field environment on the neutron star surface.The studies of X-ray burst oscillations are also crucial to understand the spinup process of neutron star low-mass X-ray binaries through accretion and the evolution into millisecond pulsars.The different characteristics of burst oscillation signals between persistent accretion-powered pulsars,intermittent accretion-powered pulsars and sources without detectable accretion-powered pulsations can help us to study more about it.We briefly introduce type Ⅰ X-ray bursts,and then specifically explain the methods to search for burst oscillations and provide the observational results of X-ray burst oscillations.The theoretical burst oscillation model,i.e.,the hot spot model,the surface mode model and the cooling wake model,are discussed.At present,we note that these models are difficult to explain all the observed phenomena of X-ray burst oscillations.In future,the China-led mission,the enhanced X-ray Timing and Polarimetry(eXTP)observatory will observe neutron star low-mass X-ray binaries and search X-ray burst oscillations.By modeling the stacking pulse profile of X-ray burst oscillation,the mass and radius of neutron star will be measured accurately,and the neutron star equation of state will be tightly constrained.We also expect more neutron stars will be measured their spin frequency,if luck,sub-millisecond pulsar will be discovered.

关 键 词：X射线暴 X射线暴振荡 小质量X射线双星 脉冲星 

分 类 号：P142.6[天文地球—天体物理]