Observational Study of the Cosmic X-ray Background with the Scientifica Satellite ASTRO-D

利用科学卫星 ASTRO-D 对宇宙 X 射线背景进行观测研究

• 批准号: 05402002
• 负责人: MAKISHIMA Kazuo
• 金额: $ 7.68万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05402002/
• 关键词: X-ray Astronomy; Cosmic X-ray Bakcground; X-ray Detector; Scientific Satellite; Deep Space Survey

The objective of this scientific project is to investigate the cosmic X-ray background (CXB), using the scientific satellite ASTRO-D (ASCA) launched on 1993 February 20, and to carry out in-orbit calibration of the GIS (Gas Imaging Spectrometer) instrument onboard ASCA.The CXB is anenigmatic phenomenon known science the birth of the X-ray astronomy, but its exact origin is still unknown. Through three years of investigation, the following achievements have been obtained.1. The in-orbit performance verification and detailed calibration of the GIS have been accomplished. In particular, the GIS particle background has been precisely quantified, which is important for the investigation of diffuse emissions including the CXB.2. By taking into account the point spread function and stray light of the X-ray telescope, a new scheme of data analysis has been developed for application to widely extended X-ray sources.3. New insight has been obtained for various extra-Galactic objects which potentially contribute to the CXB.In particular ; (1) importance of the large-scale magnetic fields has been revealed ; (2) the dark matter distribution has been found to exhibit galaxy/cluster tierarchy ; and (3) a number of low-luminosity active nuclei have been discovered in nearby normal galaxies.4. The CXB spectrum has been show to exhibit a single power-law shape with a photon index 1.4 over the 1-10 keV energy range. This contradicts the previous results obtained with the ROSAT satellite. In addition, after removing point sources brighter than 3*10^<-13> erg/s/cm^2 (in 2-10 keV), the field-to field fluctuation of te CXB surface brightness is confirmed to be <plus-minus>3% at most. These results give strong constraints to the models that attempt to synthesize the CXB as a superposition of distant objects.

该科学项目的目的是利用1993年2月20日发射的科学卫星ASTRO-D（ASCA）调查宇宙X射线背景（CXB），并对ASCA上的GIS（气体成像光谱仪）仪器进行在轨校准。CXB是X射线天文学诞生时科学上已知的神秘现象，但其确切起源仍然未知。通过三年的调研，取得了以下成果.完成了GIS的在轨性能验证和详细标定。特别是，GIS粒子背景已被精确量化，这是重要的扩散排放，包括CXB的调查。通过考虑X射线望远镜的点扩散函数和杂散光，提出了一种适用于大范围X射线源的数据分析方法。对各种可能对CXB有贡献的银河系外天体获得了新的认识，特别是：（1）揭示了大尺度磁场的重要性;（2）发现暗物质分布具有星系/星系团的时间性;（3）在邻近的正常星系中发现了许多低光度活动核。CXB光谱已被证明表现出一个单一的幂律形状的光子指数为1.4在1-10 keV的能量范围。这与以前用ROSAT卫星获得的结果相矛盾。此外，在去除亮度大于3*10^<-13>erg/s/cm ^2（2-10 keV）的点源后，teCXB表面亮度的场-场波动最大为<plus-minus>3%。这些结果给出了强有力的约束模型，试图合成CXB作为一个遥远的物体的叠加。

项目成果

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Suto, Y.等人：“本地群的 X 射线晕及其对微波和软 X 射线背景的影响”Astropjys.J.（正在出版）。

Iyomoto,N.: "Detection of Excess Hard X-ray Emission from the Jet Galaxy NGC 1097" Publ.Astron.Soc.Japan. 48(印刷中). (1996)

Iyomoto, N.：“喷气星系 NGC 1097 的过量硬 X 射线发射的检测”Publ.Astron.Soc.Japan 48（印刷中）。

Ikebe,Y.: "Discovery of a Hierarchical Distribution of Dark Matter in the Fornax Clusters of Galaxies" Nature. 379. 427-429 (1996)

Ikebe,Y.：“发现天坑星系团中暗物质的分层分布”自然。

Kaneda,H.: "Detection of Inverse-Compton X-rays from Lobes of Fornax A" Astrophys.J.Letters. 453. L13-L16 (1995)

Kaneda,H.：“从 Fornax A 瓣检测逆康普顿 X 射线”Astrophys.J.Letters。

Ikebe,Y: "Discovery of a Hierarchical Distribution of Dark Matter" Nature. 379. 427-42 (1996)

Ikebe，Y：“发现暗物质的层次分布”自然。