标题： GRB 050117：利用Swift卫星同时进行伽马射线和X射线观测 显示英文标题

标题： GRB 050117: Simultaneous Gamma-ray and X-ray Observations with the Swift Satellite

摘要： swift伽马射线暴探测器于2005年1月17日，在Swift警报望远镜触发伽马射线暴（GRB）后的193秒内，进行了首次自主的X射线后续观测。 在爆发仍在进行时，X射线望远镜（XRT）获取了一个未列入目录的X射线源的位置和图像；这与伽马射线观测同时进行。 在初始辐射期间，XRT在0.5-10千电子伏能量范围内的观测通量为1.1 x 10^{-8} ergs cm^{-2} s^{-1}。 在初始辐射之后的700秒内，X射线波段的发射强度降低了三个数量级。 当外推到XRT能量范围时，这与伽马射线的衰减一致。 在接下来的6.3小时内，XRT以自动化序列继续观测余辉947秒，直到爆发被地球边缘完全遮挡。 一个微弱且极其缓慢衰减的余辉，指数α=-0.21$, was detected. Finally, a break in the lightcurve occurred and the flux decayed with alpha<-1.2$。 X射线位置触发了许多后续观测：尽管在XRT位置附近3弧秒处发现了一个候选光学余辉，但未能确认光学余辉的存在。 显示英文摘要

摘要： The Swift Gamma-Ray Burst Explorer performed its first autonomous, X-ray follow-up to a newly detected GRB on 2005 January 17, within 193 seconds of the burst trigger by the Swift Burst Alert Telescope. While the burst was still in progress, the X-ray Telescope obtained a position and an image for an un-catalogued X-ray source; simultaneous with the gamma-ray observation. The XRT observed flux during the prompt emission was 1.1 x 10^{-8} ergs cm^{-2} s^{-1} in the 0.5-10 keV energy band. The emission in the X-ray band decreased by three orders of magnitude within 700 seconds, following the prompt emission. This is found to be consistent with the gamma-ray decay when extrapolated into the XRT energy band. During the following 6.3 hours, the XRT observed the afterglow in an automated sequence for an additional 947 seconds, until the burst became fully obscured by the Earth limb. A faint, extremely slowly decaying afterglow, alpha=-0.21$, was detected. Finally, a break in the lightcurve occurred and the flux decayed with alpha<-1.2$. The X-ray position triggered many follow-up observations: no optical afterglow could be confirmed, although a candidate was identified 3 arcsecs from the XRT position.