Jonathan E. Grindlay, Lorenzo Natalucci, EXIST Team
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9 pages, 7 figures. Accepted for publication on PoS (contribution PoS(extremesky2009)082), proceedings of "The Extreme sky: Sampling the Universe above 10 keV", held in Otranto (Italy), 13-17 October 2009
The recent hard X-ray surveys performed by INTEGRAL and Swift have started to reveal the demographics of compact sources including Super-Massive Black Holes hosted in AGNs and have proven invaluable in tracking explosive events as the death of massive stars revealed by Gamma-Ray Bursts up to cosmological distances. Whereas the observations have contributed significantly to our understanding of the sources populations in the Local Universe, it has also become evident that revealing the processes that drive the birth and evolution of the first massive stars and galaxies would have required a further big step in both sensitivity and capability to study transient phenomena since their very beginning and covering different wavebands simultaneously. Therefore, after its decennial history as a proposed hard X-ray survey mission, EXIST has now turned into a new, more advanced concept with three instruments on board covering the IR/optical and X-ray/soft gamma-ray bands. The EXIST new design (Grindlay 2009a) is therefore much improved in its capability for prompt study of GRBs (with autonomous determination of the redshift for many of them) and broadband spectral studies of SMBHs and transients in the high energy band from 0.1 to several hundred keV, with sensitive optical/NIR and soft X-ray identifications and followup studies.
Improving the low-energy transient sensitivity of AMEGO-X using single-site events
AMEGO-X,全天空中能伽马射线观测仪,是一种拟议中的仪器,旨在通过测量天空,以前所未有的灵敏度从~100 keV到大约1 GeV,弥合所谓的"MeV差距"。这一能带对于多信使和多波长研究至关重要,但目前还没有得到充分的探索。AMEGO-X通过提出一种能够通过康普顿相互作用和对产生过程检测和成像伽马射线的设计来解决这种情况。然而,AMEGO-X将研究的一些物体,如伽马射线暴和磁星,延伸到能量低于100千电子伏的地方,主要的相互作用变成光电吸收。这些事件将其能量沉积在探测器的单个像素中。在这项工作中,我们展示了如何利用AMEGO-X跟踪器的~3500 cm ^2有效面积来显著提高其灵敏度,并扩大瞬态现象的能量范围。虽然成像是不可能的单站点的事件,我们将展示我们如何将本地化的瞬变源在天空中使用其聚合信号在几度之内。这项技术将使AMEGO-X观测到的宇宙学伽马射线爆发数量增加一倍以上,使我们能够探测和分辨河外磁星巨耀斑的脉动尾部,并增加探测到的能量较低的磁星爆发数量--有些可能与快速射电暴有关。总的来说,单点事件将增加敏感的能量范围,扩大科学计划,并及时提醒社区更微弱的瞬态事件。
The Kilodegree Extremely Little Telescope: Searching for Transiting Exoplanets in the Northern and Southern Sky
Kilodegree Extremely Little Telescope(KELT)是一个地面计划,旨在寻找围绕相对明亮恒星运行的系外行星。为了实现这一目标,KELT科学小组运营着两个行星设施-位于亚利桑那州维纳天文台的KELT-North和位于南非天文台的KELT-South。这些天文台使用的望远镜具有特别宽的视野,使KELT能够研究大量潜在的系外行星宿主恒星。瞄准明亮恒星的主要优势之一是,分布在世界各地的小型地面观测站可以很容易地跟踪检测到的系外行星候选者。本文将简要概述KELT-北和KELT-南调查,KELT后续合作进行的后续观测,以及迄今为止确认的系外行星发现,最后简要讨论KELT计划的未来。
Making the unmodulated pyramid wavefront sensor smart II. First on-sky demonstration of extreme adaptive optics with deep learning
Leiden Observatory, Leiden University(莱顿大学莱顿天文台);Center for Computational Astrophysics, Flatiron Institute(弗拉铁隆研究所计算天体物理中心);Wyant College of Optical Sciences, The University of Arizona(亚利桑那大学怀恩特光学科学学院);Subaru Telescope, National Observatory of Japan, National Institutes of Natural Sciences(日本自然科学研究机构国立天文台昴星团望远镜);Astrobiology Center, National Institutes of Natural Sciences(日本自然科学研究机构天体生物学中心);Northrop Grumman Corporation(诺斯罗普·格鲁曼公司);Draper Laboratory(德雷珀实验室);Starfire Optical Range(星火光学靶场)
Extreme Scale Survey Simulation with Python Workflows
维拉C。Rubin Observatory Legacy Survey of Space and Time(LSST)将很快在多个光学波段对天空进行前所未有的广泛,快速和深入的调查。LSST的数据将在天文学和宇宙学中开辟一个新的发现空间,同时为解决当今的热点问题提供线索,例如暗能量的起源和暗物质的性质,同时产生的数据反过来又会提出新的问题。为了迎接即将到来的这一非凡数据集,相关科学团体必须能够开发出分析它所需的软件,现在可用的计算能力使我们能够生成合成数据集,这些数据集可以用作这种努力的现实训练场。这项工作提出了自己的挑战-需要生成非常大的夜空模拟,将模拟活动扩展到具有不同架构的多个计算中心的大量计算节点,并围绕内存要求和广泛变化的挂钟时间优化复杂的工作负载。我们在这里描述了一个大规模的工作流,它将Python代码融合在一起来引导工作流,Parsl管理工作流组件的大规模分布式执行,容器在多个站点上执行图像模拟活动。利用这些工具,我们开发了一个极端规模的计算框架,并使用它来模拟300平方度天空区域的五年观测。我们描述了我们的经验和教训,在开发这种工作流的能力,并强调如何的可扩展性和可移植性,我们的方法使我们能够有效地执行它高达4000个计算节点上的两台超级计算机。