Gamma-Ray Bursts: From Progenitors to Probes

该奖项用于获取和分析X射线、光学、红外、毫米和无线电波长观测数据，以研究短寿命伽马射线爆发发射(GRBs)的爆炸特性。伽玛暴是一种神秘的、瞬间的高能量现象(明显比超新星爆炸亮得多)，可能是由中子星和/或黑洞组成的双星合并造成的。研究人员还计划利用遥远来源的伽玛暴作为“手电筒”来照亮前景星系和星际介质。这些测量将被用来测量星系的化学丰度，并限制在宇宙学模型中占主导地位的再电离时代(EOR)的模型。EOR发生在宇宙只有几亿年的时候，标志着宇宙气体成分从主要中性到主要电离的转变。研究人员将把天文学研究纳入本科课程，培训和指导学生和博士后研究员，并开展公众宣传。这项工作将通过使用各种望远镜，包括JVLA、CARMA、ALMA、麦哲伦、钱德拉和双子座望远镜，集中于三个主要目标来完成。研究人员将：1)在探测到爆发后的最初几个小时到几天内，确定伽玛射线暴喷出物的组成(重子和磁性)；2)测量短伽玛暴的喷流开口角，以确定能量尺度和速率，寻找r过程动力对应物以测试预测伽玛暴是由致密天体双星产生的模型；以及3)利用伽玛暴发射测量星系的金属丰度和红移时无法直接观测到的电离，并研究z=2-5处的质量-金属丰度关系。

This award funds work to obtain and analyze X-ray, optical, infrared, millimeter and radio wavelength observations to study the explosion properties of short-lived Gamma Ray Burst emission (GRBs). GRBs are mysterious, transient highly energetic phenomena (significantly brighter than supernova explosions) that may be caused by the merger of binaries composed of neutron stars and/or a black hole. The investigators also plan to use the GRBs from very distant sources as 'flashlights' to illuminate foreground galaxies and intergalactic medium. The measurements will be used to measure the chemical enrichment of galaxies, and to constrain models of the Epoch of Re-ionization (EoR), which plays a dominant role in cosmological models. The EoR occurred when the universe was only a few hundred million years old, and marks the transition from when the universe's gaseous component changed from mostly neutral to mostly ionized. The researchers will integrate astronomy research into undergraduate courses, train and mentor students and post-doctoral fellows, and conduct public outreach. This work will be accomplished by focusing on three main goals using a variety of telescopes, including the JVLA, CARMA, ALMA, Magellan, Chandra and Gemini. The investigators will: 1) determine the composition of the GRB ejecta (baryonic vs. magnetic) in the first few hours to days after a burst is detected; 2) measure the jet opening angles of short GRBs to determine the energy scale and rate, search for r-process powered counterparts to test models that predict that GRBs are generated from compact object binaries; and 3) use GRB emission to measure galaxy metallicities and reionization at redshifts that are inaccessible to direct observations, and to study the mass-metallicity relation at z = 2 - 5.