Probing dust-obscured star formation in the most massive Gamma-Ray Burst host galaxies
Jochen Greiner, Michal J. Michalowski, Sylvio Klose, Leslie K. Hunt, Gianfranco Gentile, Peter Kamphuis, Ruben Herrero-Illana, Mark Wieringa, Thomas Krühler, Pa… 展开作者
Jochen Greiner, Michal J. Michalowski, Sylvio Klose, Leslie K. Hunt, Gianfranco Gentile, Peter Kamphuis, Ruben Herrero-Illana, Mark Wieringa, Thomas Krühler, Patricia Schady, Jonathan Elliott, John F. Graham, Eduardo Ibar, Fabian Knust, Ana Nicuesa Guelbenzu, Eliana Palazzi, Andrea Rossi, Sandra Savaglio
Due to their relation to massive stars, long-duration gamma-ray bursts (GRBs) allow pinpointing star formation in galaxies independently of redshift, dust obscuration, or galaxy mass/size, thus providing a unique tool to investigate the star-formation history over cosmic time. About half of the optical afterglows of long-duration GRBs are missed due to dust extinction, and are primarily located in the most massive GRB hosts. In order to understand this bias it is important to investigate the amount of obscured star-formation in these GRB host galaxies. Radio emission of galaxies correlates with star-formation, but does not suffer extinction as do the optical star-formation estimators. We selected 11 GRB host galaxies with either large stellar mass or large UV-/optical-based star-formation rates (SFRs) and obtained radio observations of these with the Australia Telescope Compact Array and the Karl Jansky Very Large Array. Despite intentionally selecting GRB hosts with expected high SFRs, we do not find any star-formation-related radio emission in any of our targets. Our upper limit for GRB 100621A implies that the earlier reported radio detection was due to afterglow emission. We do detect radio emission from the position of GRB 020819B, but argue that it is in large parts, if not all, due to afterglow contamination. Half of our sample has radio-derived SFR limits which are only a factor 2--3 above the optically measured SFRs. This supports other recent studies that the majority of star formation in GRB hosts is not obscured by dust.
Probing Heavily Obscured AGN in Major Galaxy Mergers Using the mm-X-ray Correlation
Pontificia Universidad Católica de Chile(智利天主教 Pontificia 大学);Universidad de Tarapacá(塔拉帕卡大学);National Radio Astronomy Observatory(美国国家射电天文台);University of Virginia(弗吉尼亚大学);Osaka University(大阪大学);RIKEN Cluster for Pioneering Research(理化学研究所先锋研究集群);Clemson University(克莱姆森大学)
No hidden monsters: Probing recently-quenched galaxies for obscured AGN with JWST-PRIMER MIRI and NIRCam
University of Nottingham(诺丁汉大学);Johns Hopkins University(约翰斯·霍普金斯大学);Space Telescope Science Institute(太空望远镜科学研究所);University of Edinburgh(爱丁堡大学);University of St Andrews(圣安德鲁斯大学)
Probing the Cosmic Web with Fast Radio Bursts. I. Scattering
Racah Institute of Physics, The Hebrew University(拉卡物理研究所,希伯来大学);Astrophysics Research Center of the Open University (ARCO), The Open University of Israel(开放大学天体物理研究中心(ARCO),以色列开放大学);Department of Natural Sciences, The Open University of Israel(自然科学系,以色列开放大学);Department of Physics, The George Washington University(物理系,乔治华盛顿大学);Department of Physics, University of California, Santa Barbara(物理系,加州大学圣塔芭芭拉分校)
The Optically Unbiased Gamma-Ray Burst Host (TOUGH) Survey. VII. The Host Galaxy Luminosity Function: Probing the Relationship Between GRBs and Star Formation to Redshift $\sim6$
Probing the cosmic web with fast radio bursts: II. Scintillation
Racah Institute of Physics, The Hebrew University(拉卡物理研究所,希伯来大学);University of Washington, Department of Astronomy(华盛顿大学天文学系);Astrophysics Research Center of the Open University (ARCO), The Open University of Israel(开放大学天体物理学研究中心(ARCO),以色列开放大学);Department of Natural Sciences, The Open University of Israel(自然科学与系,以色列开放大学);Department of Physics, The George Washington University(乔治华盛顿大学物理系);Department of Physics, University of California, Santa Barbara(加州大学圣塔芭芭拉分校物理系)
High Resolution HST Imaging Survey of Local Star-Forming Galaxies I: Spatially-Resolved Obscured Star Formation with H$α$ and Paschen-$β$ Recombination Lines
Probing episodic accretion with chemistry: CALYPSO observations of IRAM 04191+1522. Results from the CALYPSO IRAM-PdBI survey
上下文在恒星形成的最早阶段,质量吸积的过程仍然没有被完全理解:吸积率是否随着原恒星的年龄平稳地下降,或者是否存在短暂的间歇性吸积爆发?目的。我们的目标是探索是否可以理解的框架下,在一个方案中,排放化学跟踪过去的吸积爆发观测到的C $^{18}$ O和N $_2$ H $^+$发射模式对VeLLO IRAM 04191+1522。方法:我们使用高角分辨率的Plateau de Bure干涉仪(PdBI)观察C $^{18}$ O和N $_2$ H $^+$对IRAM 04191+1522的反应,这些反应是作为CALYPSO IRAM大型程序的一部分获得的。我们模拟这些观测使用化学代码与时间相关的物理结构加上一个辐射转移模块,在那里我们允许源光度的变化。结果我们发现$_2$ H-$^+$谱线的发射显示出一个中心空穴,而C-$^{18}$-O谱线的发射是紧凑的.这两条线的形态不能用基于现今内部光度(0.08 L $_{sun}$)的恒定光度模型再现。然而,N $_2$ H $^+$峰与12 L $_{sun}$的恒定光度模型一致。使用随时间变化的温度和密度分布的模型,我们表明,所观察到的N $_2$ H $^+$峰值发射确实可能是由过去的吸积爆发。这样的爆发应该发生在几百年前。结论.我们认为,在不久的过去,在IRAM 04191+1522发生了吸积爆发。如果这样的爆发在VeLLO中很常见…
Probing the Baryon Distribution with Fast Radio Bursts
The University of Sydney(悉尼大学);University of Cape Town(开普敦大学);African Institute for Mathematical Sciences(非洲数学科学研究所);Curtin University(科廷大学);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));Stanford University(斯坦福大学);Trinity College Dublin(都柏林三一学院);Stellenbosch University(斯坦陵布什大学);Aix-Marseille University(艾克斯-马赛大学);Australian National University(澳大利亚国立大学);Indian Institute of Technology, Indore(印度理工学院印多尔分校);Chinese Academy of Sciences(中国科学院);University of Chinese Academy of Sciences(中国科学院大学)