Optical and Infrared Observations of Gamma-Ray Burst Afterglows

伽马射线暴余辉的光学和红外观测

• 批准号: 0071108
• 负责人: Jules Halpern
• 金额: $ 10万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0071108&HistoricalAwards=false
• 关键词: Optical; Infrared; Observations; Gamma; Ray

ABSTRACTAST-0071108HalpernThis project has as its objective the rapid follow-up of gamma-ray burst (GRB) afterglows using ground-based, optical/IR photometry and spectroscopy on the Michigan-Dartmouth-MIT (MDM) 2.4m telescope on Kitt Peak. The PI has been one of the important players in this type of research since 1998 and has the good, prompt access to the telescope which is necessary for this type of follow-up work.Using the approximately 6 to 8 bursts per year in the northern hemisphere that are located within hours by the BeppoSAX and/or RXTE satellites, this project will continue a successful program of discovering and characterizing the optical afterglows of gamma-ray bursts with the two telescopes of the MDM Observatory. Starting with the year 2000 launch of the HETE-II satellite, it will become possible to make optical identifications within minutes of a GRB event, which affords the opportunity to obtain multicolor optical light curves on small telescopes such as the MDM1.3m, and absorption-line redshifts on medium-sized telescopes such as the MDM 2.4m.These data can be used to study the temporal decay and spectral evolution of the afterglow in order to diagnose the energetics of the fireball, and to model the circumstellar environmentsin which these explosions occur, e.g., uniform interstellar medium vs. stellar wind. HETE-II will also be sensitive to the class of short-duration gamma-ray bursts, which have heretofore not been identified, and are distinct in their gamma-ray spectral properties and flux distribution from the long-duration bursts which have triggered all previous after- glow detections. This work has the goal of revealing a distinct population of GRB progenitor, for example, old ones that have traveled outside their galaxy's interstellar medium, versus those that end their short lives while still embedded in dense, star-forming regions. Infrared photometry is of utmost importance for this distinction. Prompt IR photometry, particularly in the K band, offers the opportunity to identify thehighest redshift and/or most obscured GRBs. The MDM 2.4m and ONIS IR camera, can easily detect a moderately obscured GRB to z = 10 within an hour of the event. On longer time scales, the light curves can be followed for several days in order to discover the predicted (and occasionally detected) temporal steepening which is the signature of jet-like afterglows. Measuring such breaks is crucial to quantifying the effects of beaming on the energetics of the fireball and on the global statistics of GRBs and their afterglows. Finally, the afterglows of the brighter and closer events can be monitored for several weeks in order to search for the signatures of underlying supernovae in their late-time optical light curves. The possible association of at least some GRBs with supernovae of massive stars promises to be the long-sought handle on the physics of the GRB itself. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***

摘要-0071108Halpern该项目的目标是利用基特峰密歇根-达特茅斯-麻省理工学院 (MDM) 2.4m 望远镜上的地面光学/红外光度测量和光谱学，快速跟踪伽马射线爆发 (GRB) 余辉。自 1998 年以来，PI 一直是此类研究的重要参与者之一，并且能够快速、良好地使用望远镜，这对于此类后续工作来说是必需的。利用 BeppoSAX 和/或 RXTE 卫星在数小时内定位的北半球每年约 6 至 8 次爆发，该项目将继续使用两台望远镜发现和表征伽马射线爆发光学余辉的成功计划 MDM 天文台。从2000年发射HETE-II卫星开始，在GRB事件发生后几分钟内进行光学识别将成为可能，这提供了在MDM1.3m等小型望远镜上获得多色光变曲线和在MDM 2.4m等中型望远镜上获得吸收线红移的机会。这些数据可用于研究GRB事件的时间衰减和光谱演化。 余辉，以便诊断火球的能量，并模拟这些爆炸发生的星际环境，例如均匀的星际介质与恒星风。 HETE-II 还将对短时伽马射线爆发敏感，此类爆发迄今为止尚未被识别，并且其伽马射线光谱特性和通量分布与触发所有先前余辉探测的长持续时间爆发不同。这项工作的目标是揭示伽玛射线暴祖细胞的独特种群，例如，那些已经旅行到星系星际介质之外的古老伽玛射线暴祖细胞，以及那些结束了短暂生命但仍然嵌入在致密的恒星形成区域中的祖细胞。红外光度测定对于这种区别至关重要。快速红外光度测量，特别是在 K 波段，提供了识别最高红移和/或最模糊的伽玛暴的机会。 MDM 2.4m 和 ONIS 红外相机可以在事件发生后一小时内轻松检测到 z = 10 的适度遮挡的GRB。在较长的时间尺度上，可以跟踪光变曲线几天，以便发现预测的（偶尔检测到的）时间陡峭，这是喷射式余辉的特征。测量这种断裂对于量化辐射对火球能量以及伽玛暴及其余辉的全球统计的影响至关重要。最后，可以对更亮和更近的事件的余辉进行几周的监测，以便在其晚期光学光曲线中寻找潜在超新星的特征。至少一些伽玛暴与大质量恒星超新星的可能关联有望成为伽玛暴本身物理学的长期寻找的答案。该项目的资金由 NSF 河外天文学和宇宙学计划 (AST/EXC) 提供。***