标题： VERITAS对LS I +61$^\circ$303中 exceptionally 明亮的 TeV 谱 flare 的观测 显示英文标题

标题： VERITAS observations of exceptionally bright TeV flares from LS I +61$^\circ$ 303

摘要： 高能（VHE；E > 100 GeV）伽马射线实验VERITAS在2014年10月至12月期间从高能X射线双星LS I +61$^\circ$ 303探测到异常明亮的耀发。LS I +61$^\circ$ 303 是一个已知的VHE伽马射线源，其流量随约26.5天的轨道周期显著变化。最大VHE流量出现在近拱点（轨道相位~0.6），通常对应于蟹状星云流量（>300 GeV）的10-15%。在这次最近的观测中，在两个轨道周期（10月和11月）的近拱点附近观察到了相对较短（以天为尺度）、明亮的TeV耀发。这两种情况的峰值流量均超过蟹状星云流量的25%（>300 GeV），使这些成为该源有史以来探测到的最亮VHE耀发。在最后一个观测的轨道周期（12月），该源的活动水平恢复到历史平均水平。本文将介绍2014年VERITAS观测的这些结果。 显示英文摘要

摘要： The very-high-energy (VHE; E > 100 GeV) gamma-ray experiment, VERITAS, detected exceptionally bright flares from the high-mass X-ray binary LS I +61$^\circ$ 303 during the period October-December 2014. LS I +61$^\circ$ 303 is a known VHE gamma-ray source, the flux from which varies strongly with the orbital period of ~26.5 days. The maximum VHE flux is found around apastron (orbital phase ~0.6) at a level typically corresponding to 10-15% of the Crab Nebula flux (>300 GeV). During these most recent observations, relatively short (day scale), bright TeV flares were observed from the source around apastron in two orbital cycles (October and November). Both cases exhibited peak fluxes above 25% of the Crab Nebula flux (>300 GeV), making these the brightest VHE flares ever detected from this source. In the last orbital cycle observed (December), the source had returned to its historical level of activity. The results of these VERITAS observations from 2014 will be presented.