arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1104.5359astro-ph.HE
收藏

成像大气切伦科夫望远镜探测微弱gamma-ray源的一种新分析策略

A new analysis strategy for detection of faint gamma-ray sources with Imaging Atmospheric Cherenkov Telescopes

Yvonne Becherini, Arache Djannati-Ataï, Vincent Marandon, Michael Punch, Santiago Pita

摘要:

基于蒙特卡罗(MC)模拟和H.E.S.S.的真实背景数据,提出了一种新的立体成像大气切伦科夫望远镜(IACT)γ射线天体物理背景抑制策略。[High能量立体系统,见[1]。实验,描述。该分析是基于一个多变量组合的先前已知的和新衍生的判别变量使用的物理淋浴属性,以及它的多个图像,共八个变量。其中两个新变量的定义得益于一个新的能量评估程序,这也是在这里提出的。该方法可以提高灵敏度与当前一代的地面切伦科夫望远镜实现,并在同一时间,其主要特点的快速性和灵活性允许一个简单的推广到任何类型的IACT。用MC模拟事件对该方法对夜空背景(NSB)变化的鲁棒性进行了测试。分析链的总体一致性已通过与从H.E.S.S.获得的真实伽马射线信号的比较进行了检查。观测与MC模拟和通过重建已知的源谱。最后,通过对微弱的H.E.S.S.的应用,对该方法的性能进行了评价。源与最佳标准Hillas分析相比,灵敏度的增益范围约为1.2至1.8,取决于源特性,这对应于1.4至3.2倍的观测时间的经济性。

英文摘要:

A new background rejection strategy for gamma-ray astrophysics with stereoscopic Imaging Atmospheric Cherenkov Telescopes (IACT), based on Monte Carlo (MC) simulations and real background data from the H.E.S.S. [High Energy Stereoscopic System, see [1].] experiment, is described. The analysis is based on a multivariate combination of both previously-known and newly-derived discriminant variables using the physical shower properties, as well as its multiple images, for a total of eight variables. Two of these new variables are defined thanks to a new energy evaluation procedure, which is also presented here. The method allows an enhanced sensitivity with the current generation of ground-based Cherenkov telescopes to be achieved, and at the same time its main features of rapidity and flexibility allow an easy generalization to any type of IACT. The robustness against Night Sky Background (NSB) variations of this approach is tested with MC simulated events. The overall consistency of the analysis chain has been checked by comparison of the real gamma-ray signal obtained from H.E.S.S. observations with MC simulations and through reconstruction of known source spectra. Finally, the performance has been evaluated by application to faint H.E.S.S. sources. The gain in sensitivity as compared to the best standard Hillas analysis ranges approximately from 1.2 to 1.8 depending on the source characteristics, which corresponds to an economy in observation time of a factor 1.4 to 3.2.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑