瞬变光学天空在极短时间尺度上仍基本未被探索。尽管已有一些实验搜索从分钟到年级时间尺度的光学瞬变源,但没有任何实验具备分辨毫秒级快速光学暴(Fast Optical Bursts,FOB)的能力。这种极快瞬变源可能是快速射电暴(Fast Radio Bursts,FRB)的光学对应体、γ射线暴(γ-Ray Bursts,GRB)的瞬时辐射,或其他此前未知的现象。本文研究了一种用于偶然探测 FOB 的新方法,其核心是搜索异常的空间图像。具体而言,由于 FOB 持续时间很短,在有限时长的标准光学曝光中,受视宁度畸变的 FOB 图像应表现出与稳定光源图像明显不同的特征。我们将这一思想应用于 Vera C. Rubin 天文台的模拟观测;这些模拟通过追踪单个光子穿过湍流大气,并继续向下经过 Rubin 望远镜的光学系统和相机而生成。我们将这些模拟图像与在 15 s 积分时间(Rubin 的标称曝光时间)下得到的稳定源恒星模拟进行比较。本文报告了用于区分 FOB 与稳定源的神经网络分类器的分类准确率结果。基于该分类器,我们给出了在持续时间—强度参数空间中对 Rubin 观测中的 FOB 进行明确识别的约束条件。最后,我们估计了在为期 10 年的 Rubin 空间与时间遗留巡天(Legacy Survey of Space and Time,LSST)期间,预计可探测到的 FRB 的 FOB 对应体总数。
英文摘要:
The transient optical sky has remained largely unexplored on very short timescales. While there have been some experiments searching for optical transients from minutes to years, none have had the capability to distinguish millisecond Fast Optical Bursts (FOB). Such very fast transients could be the optical counterparts of Fast Radio Bursts (FRB), the prompt emission from $γ$-Ray Bursts (GRB), or other previously unknown phenomena. Here, we investigate a novel approach to the serendipitous detection of FOBs, which relies on searching for anomalous spatial images. In particular, due to their short duration, the seeing distorted images of FOBs should look characteristically different than those of steady sources in a standard optical exposure of finite duration. We apply this idea to simulated observations with the Vera C. Rubin Observatory, produced by tracing individual photons through a turbulent atmosphere, and down through the optics and camera of the Rubin telescope. We compare these simulated images to steady-source star simulations in 15 s integrations, the nominal Rubin exposure time. We report the classification accuracy results of a Neural Network classifier for distinguishing FOBs from steady sources. From this classifier, we derive constraints in duration-intensity parameter space for unambiguously identifying FOBs in Rubin observations. We conclude with estimates of the total number of detections of FOB counterparts to FRBs expected during the 10-year Rubin Legacy Survey of Space and Time (LSST).
Amortized Bayesian Inference for Supernovae in the Era of the Vera Rubin Observatory Using Normalizing Flows
Vera Rubin天文台将于2024年年中开始观测,这将使我们的超新星发现率提高到每年超过100万颗。人们一直在大力推动开发新的方法来识别、分类并最终理解鲁宾天文台发现的数百万颗超新星。在这里,我们提出了第一个基于模拟的推理方法,使用归一化流,训练快速推断多变量,Rubin类数据流中的玩具超新星模型的参数。我们发现,我们的方法是很好的校准相比,传统的推理方法(特别是MCMC),在测试时间只需要万分之一的CPU小时。
Blazar variability with the Vera C. Rubin Legacy Survey of Space and Time (LSST)
耀变体的辐射主要来自指向我们的相对论性喷流,是研究河外喷流及其中心引擎的基本来源,由吸积盘提供的超大质量黑洞(SMBH)组成。它们也是高能中微子和宇宙射线的候选源。由于喷流的方向,非热耀变体的发射是多普勒波束;它的变化是不可预测的,发生的时间尺度从不到一小时到几年。理解产生通量和光谱变化的不同机制需要在长时间段上良好采样的多波段光变曲线。特别是,爆发是揭示潜在物理学的最佳测试平台,特别是在多波长背景下研究时。维拉C。Rubin Legacy Survey of Space and Time(Rubin-LSST)将在六个测光波段对南部天空进行为期十年的监测,为以统计方式研究blazar可变性特征提供了强大的工具。警报系统将使我们能够触发对突出事件的后续观测,特别是在高(keV到GeV)和非常高(TeV)能量下。在这里,我们研究了模拟Rubin-LSST调查策略,目的是了解哪些节奏更适合耀变体科学。我们的指标包括光变曲线和颜色采样。我们还调查了饱和的问题,这将影响最亮的和许多耀斑源,并将对后续观测产生不利影响。
Identification and photometric classification of extragalactic transients in the Vera C. Rubin Observatory's Data Preview 1
University of North Carolina at Chapel Hill(北卡罗来纳大学教堂山分校);University of Minnesota(明尼苏达大学);Univ Claude Bernard Lyon 1(里昂第一大学);NSF NOIRLab(美国国家科学基金会NOIR天文台实验室);University of Delaware(特拉华大学);SLAC National Accelerator Laboratory(斯坦福直线加速器中心);Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory(卡弗里粒子天体物理学与宇宙学研究所(SLAC));The University of Arizona(亚利桑那大学);Yonsei University(延世大学);Duke University(杜克大学);Princeton University(普林斯顿大学);NCSA, University of Illinois at Urbana-Champaign(伊利诺伊大学厄巴纳-香槟分校国家超级计算应用中心);University of Washington(华盛顿大学);Purdue University(普渡大学);Lawrence Livermore National Laboratory(劳伦斯利弗莫尔国家实验室)
GOATS: The next generation software infrastructure for time-domain astronomy at Gemini/NOIRLab. Application to alerts from Vera C. Rubin Observatory's Legacy Survey of Space and Time
The automation of optical transient discovery and classification in Rubin-era time-domain astronomy
Northwestern University(西北大学);Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA)(天体物理学跨学科探索与研究中心);University of Minnesota(明尼苏达大学);California Institute of Technology(加州理工学院)
Fast Radio Bursts in the Era of the Vera C. Rubin Observatory's Legacy Survey of Space and Time
International Centre for Radio Astronomy Research, Curtin University(国际无线电天文研究中心,科廷大学);Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS)(南里奥格兰德联邦大学物理研究所);Australia Telescope National Facility, CSIRO Space & Astronomy(澳大利亚望远镜国家设施,CSIRO空间与天文学部);Sydney Institute for Astronomy, School of Physics, The University of Sydney(悉尼大学物理学院悉尼天体物理研究所);Department of Physics, University of Washington(华盛顿大学物理系);Centre for Astrophysics and Supercomputing, Swinburne University of Technology(斯威本科技大学天体物理学与超级计算中心);Kavli IPMU (WPI), UTIAS, The University of Tokyo(东京大学宇宙起源研究核心理论中心( Kavli IPMU));School of Mathematical and Physical Sciences, Macquarie University(麦考瑞大学数理科学学院);Department of Physics, University of Oxford(牛津大学物理系)
A Deep Learning Approach for Active Anomaly Detection of Extragalactic Transients
Columbia University(哥伦比亚大学);Princeton University(普林斯顿大学);Center for Astrophysics | Harvard & Smithsonian(哈佛与史密森尼天体物理中心);Flatiron Institute(熨斗研究所);University of Illinois at Urbana-Champaign(伊利诺伊大学厄巴纳-香槟分校)
DAVOS: Dwarf Active Galactic Nuclei from Variability for the Origins of Seeds: Properties of Variability-Selected Active Galactic Nuclei in the COSMOS Field and Expectations for the Rubin Observatory
AT2025agpz in Rubin commissioning data: distinguishing a luminous interacting supernova from nuclear transients in compact galaxies
Queen’s University Belfast(贝尔法斯特女王大学);University of Southampton(南安普顿大学);University of Oxford(牛津大学);Swinburne University of Technology(斯威本科技大学);ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav)(引力波发现卓越研究中心(OzGrav));University of Illinois(伊利诺伊大学)
Prospects for optical detections from binary neutron star mergers with the next-generation multi-messenger observatories
Gran Sasso Science Institute (GSSI)(格兰萨索科学研究所);INFN, Laboratori Nazionali Del Gran Sasso(意大利国家核物理研究所,格兰萨索国家实验室);INAF – Osservatorio Astronomico d’Abruzzo(意大利国家天体物理研究所,阿布鲁佐天文台);Department of Astronomy and Astrophysics, The Pennsylvania State University(宾夕法尼亚州立大学天文学与天体物理学系);Dipartimento di Fisica, Università di Trento(特伦托大学物理系);INFN-TIFPA, Trento Institute for Fundamental Physics and Applications(意大利国家核物理研究所-特伦托基础物理与应用研究所)