介绍了硬透视X射线调制望远镜(Insight-HXMT)的定时系统和三个有效载荷的定时标定结果。这三个有效载荷是高能X射线望远镜(HE,20-250 keV)、中能X射线望远镜(ME,5-30 keV)和低能X射线望远镜(LE,1-10 keV)。我们提出了一种方法来纠正的温度依赖的周期响应和长期变化的板载晶体振荡器,特别是对于ME,不携带温度补偿晶体振荡器。测量了蟹状星云脉冲星的到达时间(ToAs),以评估计时系统的精度。由于Jodrell Bank天文台给出的蟹状星云脉冲星星历存在约40 μs的系统误差(Rots et al. 2014),我们利用中子星内部成分探测器(NICER)上的X射线计时仪(XTI)的准同步观测数据来制作蟹状星云星历,并对Insight-HXMT的计时系统进行了验证。计算得到,高、中、低三个波段的ToAs相对于NICER测量值(包括物理源和仪器源)的能量偏移分别为24.7μs、10.1μs和864.7μs,系统的系统误差分别为12.1μs、8.6μs和15.8μs。
英文摘要:
We describe the timing system and the timing calibration results of the three payloads on-board the Insight-Hard X-ray Modulation Telescope (Insight-HXMT). These three payloads are the High Energy X-ray telescope (HE, 20-250 keV), the Medium Energy X-ray telescope (ME, 5-30 keV) and the low Energy X-ray telescope (LE, 1-10 keV). We present a method to correct the temperature-dependent period response and the long-term variation of the on-board crystal oscillator, especially for ME that does not carry a temperature-compensated crystal oscillator. The time of arrivals (ToAs) of the Crab pulsar are measured to evaluate the accuracy of the timing system. As the ephemeris of the Crab pulsar given by Jodrell Bank observatory has systematic errors around 40 μs (Rots et al. 2014), we use the quasi-simultaneous observations of the X-ray Timing Instrument (XTI) on-board the Neutron star Interior Composition Explorer (NICER) to produce the Crab ephemerides and to verify the timing system of Insight-HXMT. The energy-dependent ToAs' offsets relative to the NICER measurements including physical and instrumental origins are about 24.7μs, 10.1μs and 864.7μs, and the systematic errors of the timing system are determined as 12.1μs, 8.6μs, and 15.8μs, for HE, ME and LE respectively.
Timing of young radio pulsars I: Timing noise, periodic modulation and proper motion
年轻恒星的平稳降旋受到两种非确定性现象的扰动:毛刺和定时噪声。虽然定时噪声提供了对极端密度下的核物理和等离子体物理的见解,但它是高精度脉冲星定时实验的障碍。本文提出了一种改进的基于贝叶斯推理的方法,用于同时模拟用64 m Parkes射电望远镜观测了$\sim$ 10年的85个高$\dot{E}$射电望远镜样本的随机和确定性参数。定时噪声是一个红色的过程,我们开发了一个参数化的基础上的红色噪声幅度($A_{\rm red}$)和频谱指数($β$)。我们测量的中位数$A_{\rm red}$为$-10.4^{+1.8}_{-1.7}$ yr $^{3/2}$和$β$为$-5.2^{+3.0}_{-3.8}$,并表明定时噪声的强度与$ν^{1}|\dotν|^{-0.6\pm0.1}$成正比,其中$ν$是脉冲星的自旋频率,$\dotν$是其自旋下降率。最后,我们测量了19颗恒星的重要制动指数,两颗恒星的自行,并讨论了五颗恒星到达时间的周期性调制。
A simple, flexible method for timing cross-calibration of space missions
Saitama University(埼玉大学);Ehime University(爱媛大学);NASA Goddard Space Flight Center(美国国家航空航天局戈达德太空飞行中心);RIKEN Nishina Center(理化学研究所仁科加速器研究中心);Tokyo University of Science(东京科学大学);Tor Vergata University of Rome(罗马托尔维加塔大学);University of Maryland, Baltimore County(马里兰大学巴尔的摩县分校);Rikkyo University(立教大学);Kanazawa University(金泽大学);RIKEN Pioneering Research Institute(理化学研究所先锋研究本部);New York University Abu Dhabi(纽约大学阿布扎比分校)
A Falsifiable Timing Test for the Double-White-Dwarf Model of Long-Period Transients
School of Astronomy and Space Science, Nanjing University(南京大学天文与空间科学学院);Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education(教育部现代天文学与天体物理重点实验室(南京大学))
Multi-mission Investigation of X-ray Superorbital Modulation in the Supergiant High Mass X-ray Binary 4U 1538-52
The Catholic University of America(美国天主教大学);University of Maryland, Baltimore County(马里兰大学巴尔的摩县分校);NASA Goddard Space Flight Center(美国宇航局戈达德太空飞行中心);Maryland Institute College of Art(马里兰艺术学院)