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2016.05.01 学术报告:寻找宇宙重子

时间:2016-04-29  来源:文本大小:【 |  | 】  【打印

  报告题目:寻找宇宙重子 

  时间:201651日,上午900 

  地点:条纹相机工程中心三楼大会议室 

  报告人:崔伟 教授 

    

  报告摘要:One of the triumphs of the Big Bang Nucleosynthesis (BBN) theory is that its predicted abundances of primordial isotopes agree with the measured values. Moreover, the predicted baryonic mass is accounted for at high redshifts observationally. Going towards low redshifts, however, only a fraction of the BBN baryons are detected; this is the “missing baryon” problem. The common wisdom is that those baryons are not missing, but are hidden in some warm-hot gas of very low density, which is difficult to detect; cosmological simulations support this view. Such gas may be “seen” through the emission or absorption lines of its highly ionized constituents. For that, an X-ray spectrometer of high throughput and high resolution would likely be required. I will describe the development of microcalorimeters for X-ray spectroscopy. I will also briefly discuss the design of a satellite experiment that employs the microcalorimeters to carry out a survey of warm-hot gas in the universe, addressing a wide range of important issues in astrophysics, including the “missing baryon” problem. 

  报告人简介: 

  崔伟,美国普渡大学(Purdue University)天体物理学教授,研究领域包括:超新星遗迹,宇宙射线,星际和星系际介质,X射线背景辐射,以及 X射线天体物理实验测量仪器与卫星载荷技术。崔伟教授参与过NASA及其他航天组织的多项宇宙探测任务,其中包括X-ray Quantum Calorimeter (XQC) Experiment, Rossi X-ray TimingExplorer (RXTE), Very Energetic Radiation Imaging Telescope Array System (VERITAS), LargeSynoptic Survey Telescope (LSST,大型巡天望远镜),在极紫外及X射线探测器航天载荷研制方面具有丰富经验。崔伟教授为美国天文学会、美国物理学会,国际天体联合会、SPIE等学会成员,发表论文170余篇,H-index 52