HXMT的空间环境本底计算

硬X射线调制望远镜(HXMT)是一颗宽波段X射线(1～250 keV)天文卫星,其核心载荷高能X射线望远镜(HE)工作于硬X射线能区(20～250 keV),致力于实现硬X射线的高灵敏度巡天观测,描绘硬X射线天图,并对特殊天体作高灵敏度定点观测.为了获得高灵敏度,必须有效地抑制本底.本底主要是由轨道环境中的粒子(γ射线、质子、电子、中子)与探测器相互作用产生的.本文结合大量的描述近地空间本底的文献和最新的实测数据,整理出一套自洽的近地空间本底粒子的数据和公式,便于应用.并通过Geant 4软件模拟计算给出了HXMT的本底及本底随时间和轨道的变化.      

HXMT卫星长期任务规划算法

硬X射线调制望远镜（HXMT）卫星是中国首颗空间X射线天文卫星.为充分利用卫星资源,使科学产出最大化,需要进行长期任务规划.长期任务规划是一个复杂的多目标优化问题.通过分析HXMT观测特点和约束条件,建立了HXMT长期任务规划问题模型,并采用贪婪算法加遗传算法对模型进行求解.实例分析结果表明该方法能够有效解决HXMT长期任务规划问题.      

Status of the Hard X-ray Modulation Telescope (Insight-HXMT) Project

The Hard X-ray Modulation Telescope (HXMT) was launched at Jiuquan Satellite Launch Center on June 15, 2017, and was named as Insight-HXMT after the launch. Now all the instruments work properly in space, dozens of sources have been observed, and some early scientific results have been published. The nominal lifetime of Insight-HXMT is 4 years.      

Status of the Hard X-ray Modulation Telescope Project

The Hard X-ray Modulation Telescope (HXMT) is China's first X-ray (1-250 keV) astronomical satellite officially approved in 2011. It will scan the Galactic plane to detect new transient sources and do pointed observations of X-ray sources to study their spectra and multiwavelength temporal properties. Now the flight model of the satellite is in the final testing stage, and the expected launch date is in late 2016.      

Progress on Space Solar Telescope in 2004 - 2006

The progress on Chinese Space Solar Telescope (SST) in 2004-2006 is introduced. The scientific objectives are further clarified and the ground operation system has been planned. The 7 key technical problems of SST satellite platform and payloads have been tackled, which lay solid scientific and technological foundations for engineering prototype phase of the SST project. At present the SST project undergoes evaluation by CNSA and CAS so as to enter the engineering prototype phase of the SST project if it is finally approved.     

Modeling the spectral evolution in the decaying tail of gamma-ray bursts observed by Swift

The detailed study of the spectral evolution during the steep decay phase of early X-ray light curves of gamma-ray bursts (GRBs) is a very important task that can give us information on different emission components contributing to the prompt-to-afterglow transition and help to understand the link between these two stages. Time resolved spectral analysis of bright GRBs detected by Swift has shown that a good modeling of the early X-ray light curves can be obtained with Band or cut-off power-law broad band spectra with evolving parameters (e.g., decaying peak energy). We developed a procedure to simultaneously fit the temporal evolution of all the spectral parameters of a GRB during the prompt-to-afterglow transition based on the analysis of the Swift Burst Alert Telescope (BAT) and the Swift X-ray Telescope (XRT) count rate and hardness ratio light curves. The procedure has been tested on GRB 060614 and GRB 090618, two very peculiar bright GRB detected by Swift that show a long exponentially decaying tail with strong softening and peak energy crossing the XRT energy band.     

The Swift GRB MIDEX mission

Swift is a first-of-its-kind multiwavelength transient observatory for γ-ray burst astronomy. It has the optimum capabilities for the next breakthroughs in determining the origin of γ-ray bursts and their afterglows, as well as for using bursts to probe the early Universe. Swift will also monitor the soft gamma repeaters and perform the first sensitive hard X-ray survey of the sky. The mission is being developed by an international collaboration and consists of three instruments, the Burst Alert Telescope (BAT), the X-ray Telescope (XRT), and the Ultraviolet and Optical Telescope (UVOT). The BAT, a wide-field γ-ray detector, will detect >100 γ-ray bursts per year with a sensitivity 5× that of BATSE. The sensitive narrow-field XRT and UVOT will be autonomously slewed to the burst location within 20–70 s to determine 0.3–5.0″ positions and perform optical, UV, and X-ray spectrophotometry. Strong education/public outreach and follow-up programs will help to engage the public and the astronomical community. Swift launch is planned for late 2004.     

Analysis of long duration flares

Yohkoh has observed many long duration events permitting a statistical study of the properties of these interesting events. We have selected ten flares for analysis which have durations between 5 and 20 hours, and size ranging from C to X GOES class. Employing the Soft X-ray Telescope, the Bragg Crystal Spectrometer, GOES spacecraft, and ground-based H data, we examine the morphology, temperature, emission measure, location of the hard X-ray source, non-thermal velocities and upflows of the plasma at different stages in the flare development. Our results are used to address the question of the energy source that maintains the hot plasma at temperatures of several million degrees for many hours.     

Future X-ray astronomy missions of Japan

Japanese future space programs for high energy astrophysics are presented. The Astro-E2 mission which is the recovery mission of the lost Astro-E has been approved and now scheduled to be put in orbit in early 2005. The design of the whole spacecraft remains the same as that of Astro-E, except for some improvements in the scientific instruments. In spite of the five years of delay, Astro-E2 is still powerful and timely X-ray mission, because of the high energy resolution spectroscopy (FWHM 6 eV in 0.3–10 keV) and high-sensitivity wide-band spectroscopy (0.3–600 keV). The NeXT (New X-ray Telescope) mission, which we propose to have around 2010, succeeds and extends the science which Astro-E2 will open. It will carry five or six sets of X-ray telescopes which utilize super-mirror technology to enable hard X-ray imaging up to 60–80 keV. In mid-2010s, we would participate in the European XEUS mission, which explores the early (z>5) “hot” universe.     

The occurrence of single hard X-raysources in solar flares

The ‘standard’ thick target flare model predicts the existence of strong hard X-ray emission at the footpointsof a flare loop. However, Yohkoh observations suggest that up to 20% of events with data available in three or more Hard X-ray Telescope (HXT) channels show only a single source. Combining datasets from Yohkoh, the Solar and Heliospheric Observatory (SOHO), and Nobeyama Radio Heliograph (NoRH), we compare the characteristics of these single source events to double source events. The objective of this study is to determine whether these represent unresolved double footpoints, asymmetric electron deposition due to magnetic mirroring effects, or a genuine departure from the ‘standard’ model.     

An investigation of small GOES flares with intense hard X-ray bursts

Most solar flare observations show that intense hard X-ray bursts come from large flares that have a large GOES classification (large peak 1 – 8 Å flux). This correlation, known as the “Big Flare Syndrome”, suggests that more intense flares tend to have harder spectra. We have observed 7 flares that are exceptions to this. These flares have small GOES classifications ranging from B1.4 to C5.5 and peak hard X-ray count rates similar to those often observed from M class flares. This paper examines the cause of this anomoly using the Yohkoh Soft X-Ray Telescope, Hard X-Ray Telescope, and Bragg Crystal Spectrometer. Two hypotheses are proposed for the exceptions: (1) flares with multiple magnetic loops and common footpoints, producing multiple hard X-ray emission regions and low density thermal plasma distributed over a large volume, and (2) high densities in the magnetic loops restricting the propagation of the non-thermal electrons in the loop after magnetic reconnection has occurred and suppressing chromospheric evaporation. Two of the flares support the first hypothesis. The other flares either have data missing or are too small to be properly analysed by the Yohkoh instruments.     

Data storage and real time observations at the Mexican Array Radio Telescope

The tracking of large-scale interplanetary (IP) disturbances traveling from the Sun to the Earth is a key issue in space weather studies. The Mexican Array Radio Telescope (MEXART) applies the Interplanetary Scintillation (IPS) technique to detect these solar wind disturbances and it will participate in a global warning network of space weather forecasting. We describe the data storage and computational processes carried out to manage the instrument’s real time data. These procedures are important for the MEXART calibration, operation and the scientific data reduction.     

Space Astronomy in China:2002-2004

More and more proposals, or potential projects have been proposed in recent two years. We try to briefly outline these new proposals, although most of them are in fact only in their conception studies. The progress of previously mentioned projects, like Space Solar Telescope (SST), the Hard X-ray Modulation Telescope (HXMT), as well as newly initiated LUnar Resource Explorer (LUREX), will be introduced elsewhere.     

Microwave Brightness Temperature and Lunar Son Dielectric Property Retrieve

Among many scientific objectives of lunar exploration, investigations on lunar soil become more and more attractive to the scientists duo to the existence of abundant 3He and ilmenite in the lunar soil and their possible utilization. Although the soil composition determination on the lunar surface is available by visible light spectrometer, γ/X-ray spectrometer etc, the evaluations on the total reserves of 3He and ilmenite in the lunar deep and on the thickness of the lunar soil are still impossible so far. In this paper, the authors first give a rough analysis of the microwave brightness temperature images of the lunar disc observed using the NRAO 12 Meter Telescope and Siberian Solar Radio Telescope; then introduce our researches on the microwave dielectric properties of lunar soil simulators; finally, discuss some basic relations between the microwave brightness temperature and lunar soil properties.     

GMRT monitoring of Cyg X-1 and Cyg X-3

We present the results of low frequency radio observations of the X-ray binaries, Cygnus X-1 and Cygnus X-3, during different X-ray states. The low frequency observations were made for the first time for these sources at 0.61 and 1.28 GHz using the Giant Meter-wave Radio Telescope (GMRT) between 2003 and 2004. Both Cyg X-1 and Cyg X-3 are highly variable at low radio frequencies. We also compare our data with the observations at 15 GHz conducted by the Ryle telescope. Spectral turnover is seen for both the sources below 2 GHz. The data suggest that the change in the radio flux density in both the sources is correlated to the X-ray hardness ratio and follows a similar behavior pattern.     

Progress on Solar Physics Research in China

The progress on Chinese Space Solar Telescope (SST) in 2002-2004 is introduced. The documentations on plans and outlines based on the standards of Chinese aerospace industry for SST mission has been fulfilled. The key technical problems of SST satellite platform and payloads are tackled during pre-study stage of the mission. The laboratory assembly and calibration of the main optical telescope of 1.2 m spherical mirror and 1 m plain mirror have been carried out with the accuracy of λ/40 and λ/30, respectively. The prototype at 17.1 nm for extreme ultraviolet telescope is under development and manufacture with a diameter of 13 cm. Its primary and secondary mirrors have a manufacturing error of 5 nm with a roughness degree of less than 0.5 nm and a multiplayer reflection factor of better than 20%. The on-board scientific data processing unit has been developed. Prototypes for other payloads such as H. and white light telescope, wide band spectroscopy in high energy and solar and interplanetary radio spectrometer have been developed accordingly.     

Status of the Hard X-ray Modulation Telescope Project

The Hard X-ray Modulation Telescope (HXMT) is China's first astronomical satellite. It will perform a broad band (1-250keV) scan survey and do pointed observations of X-ray sources to study their spectra and multi-wavelength temporal properties. The pre-flight models of the satellites have been finished, and the flight models are in production. The expected launch date of HXMT is in late 2015.      

Progress on Space Solar Telescope in 2002-2004

The progress on Chinese Space Solar Telescope (SST) in 2002-2004 is introduced. The documentations on plans and outlines based on the standards of Chinese aerospace industry for SST mission has been fulfilled. The key technical problems of SST satellite platform and payloads are tackled during pre-study stage of the mission. The laboratory assembly and calibration of the main optical telescope of 1.2 m spherical mirror and 1 m plain mirror have been carried out with the accuracy of λ/40 and λ/30, respectively. The prototype at 17.1 nm for extreme ultraviolet telescope is under development and manufacture with a diameter of 13 cm. Its primary and secondary mirrors have a manufacturing error of 5nm with a roughness degree of less than 0.5 nm and a multiplayer reflection factor of better than 20%. The on-board scientific data processing unit has been developed. Prototypes for other payloads such as H and white light telescope, wide band spectroscopy in high energy and solar and interplanetary radio spectrometer have been developed accordingly.     

Diagnostics of hot thermal plasma in flare-associated X-ray ejections

This is the first analysis of the soft X-ray spectra of flare-associated X-ray ejections. For this aim, the Yohkoh Bragg Crystal Spectrometer data recorded before two behind-the-limb flares were selected. These flares came into view from behind the solar limb but their occurrence was preceded by an X-ray ejection which expanded faster. In consequence, for several minutes the X-ray ejection was seen alone, without the presence of the brighter flare. Parameters of the plasma obtained from a fitting of synthetic spectra to observed spectra are presented and compared to images from the Yohkoh Soft X-ray Telescope. The presence of a minor fraction of the very hot (∼30 MK) thermal plasma in X-ray ejections is confirmed. High values of the non-thermal line broadening are caused by a large extension of X-ray ejections.     

“Biospherics” approach for studies of natural and artificial ecosystems

The main unifying feature of natural and artificial ecosystems is their biotic turnover (cycling) of substances which is induced with energy fluxes. A new integrating scientific discipline – Biospherics – studies biotic cycles (both in experiments and in mathematical models) of different degree of closure and complexity. By its origin, Biospherics is to be connected with extensive studies of Biosphere by Russian academician Vladimir Vernadsky. He developed and used “empirical generalizations” based on innumerous observations, comparisons and reflections. His “bio-geo-chemical principles” of Biosphere and ecosystems development have more qualitative than quantitative nature. Quantitative criteria to evaluate the efficiency of natural and artificial ecosystems are to take into account energy fluxes and their use in ecosystems of different types. At least, three of them are of value for estimation of natural and artificial ecosystems’ functional activities. Energy principle of extensive development (EPED), energy principle of intensive development (EPID) and main universal (generalized) criterion (MUC). The last criterion (Principle) characterizes the specific cycling rate of limiting chemical elements in multi-organism systems, developing under external energy fluxes. Its value can be a quantitative measure of effectiveness for every ecosystem functioning, including our global Biosphere. Different examples of these (above-mentioned) integrated criteria actions are presented and analyzed in the paper.