Probing Gamma-ray Bursts and their Progenitors with Multiwavelength Observations

用多波长观测探测伽马射线暴及其前体

• 批准号: 0098676
• 负责人: Shrinivas Kulkarni
• 金额: $ 25万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0098676&HistoricalAwards=false
• 关键词: Probing; Gamma; ray; Bursts; their

AST 0098676KulkarniCosmic gamma-ray bursts (GRBs) are among the most spectacular, known phenomena in the universe. They consist of short outbursts (fractions of seconds to a few minutes) of high-energy radiation originating in distant regions of the universe, There are a few such outbursts observed per day. These were first observed by the US Vela satellites in the early 1960's. They have remained one of the major mysteries of astrophysics for the past 30 years. In the late 1990's breakthrough discoveries found that the bursts originated in faint galaxies, at typical distances of several billion light years. Measurements of distances to the bursts, using large, ground-based telescopes, revealed that apparently some of them emit prodigious amounts of energy; larger than the total amount of energy produced by our Sun over its entire projected lifespan of about 10 billion years, but compressed into a few seconds! While theories abound, the ultimate cause of these amazing cosmic explosions remains unknown. However, it now seems likely that at least some bursts represent "birth cries" of black holes, produced in the explosion of massive stars ("hypernovas"). Current research suggests that the GRB phenomenon is closely related to the history of star formation in the universe, and that it can be used as a novel probe of early cosmic evolution. It is also likely that most GRBs produce highly collimated jets of very energetic particles and radiation, effectively becoming giant acceleratorsin the sky. While a lot has been learned over the past few years, much more remains to be found about the source and the ultimate physical mechanism behind these remarkable cosmic explosions. The keys to this further understanding lies in (1) detailed observations of their afterglows seen at wavelengths ranging from radio waves, through visible light and out to x-rays; (2) additional measurements of the distances to these enigmatic events; and (3) a better understanding of their environments and the distant galaxies in which they originate. This is the subject of the presentproject. Using the worlds largest optical/infrared telescopes (the 10-m Keck telescopes in Hawaii and the large telescopes at Mt. Palomar in California), and the world's premier radio telescopes (e.g., the Very Large Array in New Mexico) to observe GRBs when they are first identified and to continue to observe them as they decline in brightness, the goal is to construct a wide enough bank of data to permit testing and winnowing of the scores of theoretical models presently under study. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***

AST 0098676Kulkarnicosmic伽马射线爆发（GRB）是宇宙中最壮观，已知的现象之一。 它们由源自宇宙遥远地区的高能辐射（几秒钟到几分钟的馏分）组成，每天观察到一些这样的爆发。 这些是1960年代初的美国Vela卫星首先观察到的。在过去的30年中，它们一直是天体物理学的主要奥秘之一。在1990年代后期，突破性发现发现，爆发源于微弱的星系，在数十亿光年的典型距离处。 使用大型地面望远镜的距离距离的测量表明，其中一些显然发出了大量的能量。大于太阳在整个预计的寿命约100亿年中产生的总能量，但被压缩到几秒钟！ 尽管理论丰富，但这些惊人的宇宙爆炸的最终原因仍然未知。 但是，现在似乎至少有些爆发代表了黑洞的“出生哭泣”，这是在大型恒星爆炸中产生的（“ Hypernovas”）。 当前的研究表明，GRB现象与宇宙中恒星形成的历史密切相关，并且可以用作早期宇宙进化的新型探针。 大多数GRB也可能产生高度精力充沛的颗粒和辐射的喷射，有效地成为天空中的巨型加速器。 尽管在过去的几年中已经学到了很多东西，但有关这些巨大宇宙爆炸背后的来源和最终物理机制仍有更多的发现。这种进一步理解的关键在于（1）详细观察到其余波的详细观察，从无线电波到可见光到X射线，范围从无线电波到X射线。 （2）对这些神秘事件的距离进行的其他测量； （3）更好地理解其环境和遥远的星系。 这是当前项目的主题。 使用世界上最大的光学/红外望远镜（夏威夷的10毫米凯克望远镜和加利福尼亚帕洛马尔山的大型望远镜），以及世界上首要的无线电台望远镜，例如，在新墨西哥州非常大的范围内，他们可以在范围内识别出足够的范围，以便他们在范围内进行依据，并可以将其置于范围内，以弥补其范围，以实现其范围，并可以将其定位为亮点，以实现精力，并可以将其定为亮点。目前正在研究的理论模型得分的测试和奖励。该项目的资金由NSF外乳术天文学和宇宙学计划（AST/EXC）提供。***