Open Exploration of the Time Domain with the Catalina Real-Time Transient Survey

通过 Catalina 实时瞬态勘测对时域进行开放式探索

• 批准号: 1313422
• 负责人: Stanislav Djorgovski
• 金额: $ 23.4万
• 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: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1313422&HistoricalAwards=false
• 关键词: Open; Exploration; Time; Domain; Catalina

Exploration of the time domain - discovery and studies of objects and phenomena changing on time scales ranging from seconds to years - is now one of the most vibrant and rapidly developing fields of astronomy, touching on a broad and diverse spectrum of research areas, from the Solar system and discoveries of exoplanets to the distant quasars, and from stellar astrophysics to cosmology and extreme relativistic astrophysics. Time domain information is essential for understanding of some of the most interesting phenomena we observe; for example, we could not learn anything from a single picture of a Supernova, or a single snapshot of a gamma-ray burst; variability of stars aids to our understanding of their structure and evolution; motions of stars tell us about the structure of our Galaxy. We now study the universe and its major constituents as a dynamical, and always changing system. This change was enabled by the progress in information technology. For many years now, large digital sky surveys have been the main sources of data in astronomy. While they can be seen as panoramic cosmic photography, we are now moving into a panoramic cosmic cinematography, with a corresponding increase in information volumes and quality: digital synoptic sky surveys which cover the sky many times, detecting objects and phenomena which change or move. This trend will culminate in the Large Synoptic Survey Telescope (LSST) years from now, but we are already exploring the science and technology of time-domain astronomy with precursor surveys. They already have a significant potential for discovery, and will help us sharpen our questions and strategies for the larger surveys in the future.This project is a continuation and substantial expansion of the Catalina Real-Time Transient Survey (CRTS), an ongoing, productive synoptic sky survey that is producing a steady stream of astronomical transient events, and making them immediately available to the entire community; it is the only current sky survey that does so. It utilizes a data stream obtained in a search for near-Earth and planetary hazard asteroids, funded by NASA, and it leverages considerable existing investments in software and data services. We have established an extensive web of collaborations for the follow-up observations and data analysis. These substantial external resources come at no cost to the NSF, and provide for much greater scientific returns on investment than what could be done with a fully funded, new survey.The overall scientific goal of CRTS is a systematic exploration of the faint, variable sky. CRTS has so far discovered ~6,500 distinct transient events, and 13 million variable sources, including a wide variety of variable stars, active galactic nuclei, various cosmic explosions, stellar flares, etc. For at least 2 years in a row, CRTS has published more Supernovae (SNe) than any other survey, including the most luminous SNe ever seen, long-predicted SNe from AGN accretion disks, hundreds of dwarf novae and other interesting cataclysmic variables, planets around white dwarfs, new counterparts of x-ray sources, new tidal streams in the Galactic halo, etc. In addition to a plenty of known types of objects and phenomena, there is a real possibility of a discovery of previously unknown kinds. This project will continue these studies, and start a number of new ones, that touch on a variety of open astronomical challenges. The unique open data policy of CRTS enables the entire astronomical community to partake in these discoveries. All transient events are published electronically in real time, and all data (images, catalogs, etc.) are also made publicly available; they will enable a broad range of archival science. CRTS may be a showcase for the data sharing and re-use, that must become a standard practice in the 21st century.This project will aid the entire astronomical community in making new discoveries and developing new scientific strategies. It is an example of a new generation of scientific experiments involving real-time mining of massive data streams, and dynamical follow-up strategies. We train undergraduate and graduate students and postdocs, the future science and technology leaders, and develop a broad variety of educational and public outreach materials, both for the new science and computation.

时域探索——发现和研究在从秒到年的时间尺度上变化的物体和现象——现在是天文学中最具活力和快速发展的领域之一，涉及广泛而多样的研究领域，从太阳系和系外行星的发现到遥远的类星体，从恒星天体物理学到宇宙学和极端相对论天体物理学。时域信息对于理解我们观察到的一些最有趣的现象至关重要；例如，我们无法从超新星的单张图片或伽马射线暴的单张快照中了解到任何信息；恒星的变异性有助于我们了解它们的结构和演化；恒星的运动告诉我们银河系的结构。我们现在将宇宙及其主要成分视为一个动态且不断变化的系统来研究。这种变化是由于信息技术的进步而实现的。多年来，大型数字巡天一直是天文学数据的主要来源。虽然它们可以被视为全景宇宙摄影，但我们现在正在进入全景宇宙电影摄影，信息量和质量相应增加：数字天气巡天多次覆盖天空，探测变化或移动的物体和现象。这种趋势将在数年后的大型综合巡天望远镜（LSST）中达到顶峰，但我们已经在通过前兆巡天探索时域天文学的科学和技术。它们已经具有巨大的发现潜力，并将帮助我们在未来进行更大规模的调查时提高我们的问题和策略。该项目是卡塔利娜实时瞬变调查（CRTS）的延续和实质性扩展，这是一项正在进行的、富有成效的天气观测天空调查，正在产生源源不断的天文瞬变事件，并立即向整个社区提供；这是目前唯一这样做的天空调查。它利用了由美国宇航局资助的近地和行星危险小行星搜索中获得的数据流，并利用了在软件和数据服务方面的大量现有投资。我们为后续观察和数据分析建立了广泛的合作网络。这些大量的外部资源对 NSF 来说是免费的，并且比完全资助的新调查所能提供的科学投资回报要大得多。CRTS 的总体科学目标是对微弱、多变的天空进行系统探索。迄今为止，CRTS 已发现约 6,500 个不同的瞬变事件和 1300 万个可变源，包括各种变星、活跃星系核、各种宇宙爆炸、恒星耀斑等。至少连续 2 年，CRTS 发布的超新星 (SNe) 数量比任何其他调查都多，包括有史以来最亮的 SNe、来自 AGN 吸积盘的长期预测的 SNe、数百个 矮新星和其他有趣的灾难变星、白矮星周围的行星、X射线源的新对应物、银河晕中的新潮汐流等。除了大量已知类型的物体和现象之外，确实有可能发现以前未知的种类。该项目将继续这些研究，并启动一些新的研究，涉及各种开放的天文学挑战。 CRTS独特的开放数据政策使整个天文学界都能参与这些发现。所有瞬态事件均以电子方式实时发布，所有数据（图像、目录等）也均公开；它们将使广泛的档案科学成为可能。 CRTS 可能是数据共享和重用的展示，这必须成为 21 世纪的标准实践。该项目将帮助整个天文学界做出新发现并制定新的科学策略。它是新一代科学实验涉及海量数据流实时挖掘和动态后续策略的一个例子。我们培训本科生、研究生和博士后，他们是未来的科学技术领导者，并为新科学和计算开发各种教育和公共宣传材料。