Optical and Infrared Observations of Gamma-Ray Burst Afterglows

利用MDM天文台的两个望远镜发现和描述伽玛射线暴（GRBs）的光学余辉的成功项目将继续并扩大，以利用HETE-2和Swift空间任务增加的事件速率和预期的快速位置，并纳入红外光度测定。在这项为期三年的计划的第一年，每年将继续对北半球大约6-8次爆发进行目标观测，这些爆发将在几小时内由BeppoSAX、RXTE和/或HETE-2卫星定位。在第二年和第三年，从2003年发射的雨燕开始，预期的定位率将增加到可以在两台望远镜上安排具体的、协调的观测计划的程度。该团队将有可能在几分钟内完成GRB事件的光学识别，这为在MDM 1.3m望远镜上获得多色光学光曲线以及在MDM 2.4m上进行红外光曲线或随时间变化的吸收线研究提供了机会。调查人员将能够以迅速、协调的方式对每年大约十几个这样的定位做出反应。这些数据将用于研究GRB余辉的时间衰减和光谱演化，以诊断火球的能量学，并诊断这些爆炸发生的星周环境，例如均匀ISM，恒星风或超级气泡

AST-0206051Halpern, Jules P.The successful program of discovering and characterizing the optical afterglows ofgamma-ray bursts (GRBs) using the two telescopes of the MDM Observatory will be continued and expanded to take advantage of the increased event rate and prompt positions expected from the HETE-2 and Swift space missions, and to incorporate infrared photometry. In the first year of this three-year program, target-of-opportunity observations will be continued based on approximately 6-8 bursts per year in the northern hemisphere that are located within hours by the BeppoSAX, RXTE, and/or HETE-2 satellites. In the second and third years, beginning with the year 2003 launch of Swift, the expected localization rate will increase to the point at which it will become feasible to schedule specific, coordinated observing programs on both telescopes. It will become possible for this team to make optical identifications within minutes of a GRB event, which affords the opportunity to obtain multicolor optical light curves on the MDM 1.3m telescope, and either infrared light curves or time-dependent absorption-line studies on the MDM 2.4m. The investigators will be able to respond in a prompt, coordinated way to about a dozen such localizations per year. These data will be used to study the temporal decay and spectral evolution of GRB afterglows in order to diagnose the energetics of the fireball, and to diagnose the circumstellar environments in which these explosions occur, e.g., uniform ISM, stellar wind, or superbubble.***