中子星双星的科学问题-IndicoIHEP.PDF

中子星双星的科学问题 极端密度条件下的中子星物态 余文飞纪龙葛明玉张澍闫震 Tuesday, January 21, 14 kHz QPO, ISCO and Neutron Star EOS Innermost Stable Circular Orbit (ISCO) -- constrain NS mass radius 6GM ∼ M RI SCO = c2 ⇠ 12.5 ( 1.4 M ) km When site of signal approaches the ISCO: from Miller et al. 1998 No stable orbital motion is expected to be detected below ISCO radius! = coherence drop or disappearance of QPOs Current RXTE data is not good enough to trace the disappearance of QPOs 2 Tuesday, January 21, 14 Determine Neutron Star Spin Rates from Burst Oscillations Millisecond Pulsations Burst Oscillations pulse profile as a probe of NS mass-radius relation Very good soft X-ray coverage with XTP ~ 7500 cm^2@1keV (3.5 times of Nicer) Tuesday, January 21, 14 模拟目标1 1. 中子星双星中千赫兹准周期振荡最高频率探测和对NS物态的限制 模拟目标和拟解决的问题： Sco X-1： 最低极限幅度光变信号探测 脉冲信号和边频、倍频探测 死时间和数据模式 4U 1608-52： 千赫兹准周期振荡脉冲轮廓 4U 1820-30： 千赫兹准周期振荡和流量的关系 Tuesday, January 21, 14 Sco X-1 利用XSPEC产生XTP 的观测谱，采用能 谱参数 (D’Ai et al. 2007, ApJ, 667, 411 ） 10 ks 观测 - 1.9 x 10 ^8 光子 （？） 探测脉冲rms幅度： - 0.1% Tuesday, January 21, 14 4U 1608-52 • 观测到最相干千赫兹准 周期振荡信号 • 研究探测千赫兹QPO幅 度和流量的关系 • 模拟：64s和256s观测 • 研究探测千赫兹QPO单 个脉冲 Tuesday, January 21, 14 4U