A new population of very high-energy gamma-ray sources detected with H.E.S.S. in the inner part of the Milky Way
A new population of very high-energy gamma-ray sources detected with H.E.S.S. in the inner part of the Milky Way
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H.E.S.S. 检测到一批新的极高能伽马射线源。
DOI：
10.11588/heidok.00005542
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
S. Funk
中科院分区：
文献类型：
--
作者：
S. Funk
高能立体观测系统（H.E.S.S.）实验是由四台成像切伦科夫望远镜组成的阵列，旨在探测能量高于100GeV的伽马射线。这些望远镜采用立体观测方法，即通过硬件层面的中央触发系统连接多台望远镜同时观测大气中的粒子簇射。这种方法极大地降低了仪器的本底，从而能够降低能量阈值并提高系统的灵敏度。本文介绍了H.E.S.S.中央触发系统的功能和性能。利用降低的能量阈值和提高的灵敏度，2004年使用H.E.S.S.以空前的灵敏度水平对银河系内部进行了甚高能伽马射线巡天观测。对相对于银河系中心经度在±30°、纬度在±3°范围内的银道面总共观测了230小时，在能量高于200GeV时达到了蟹状星云3%的平均流量灵敏度。除了该区域先前已知的三个源之外，还探测到了14个显著性水平大于4倍标准差的新源。提供了这些新源的详细光谱和形态信息，并讨论了在其他波段可能存在的对应体。探测到的源在银纬上的分布似乎与银河系盘中母体族群小于100秒差距的标高相一致。
The H.E.S.S., experiment (High Energy Stereoscopic System) is an array of four imaging Cherenkov telescopes designed to detect gamma-rays in the energy domain above 100 GeV. The telescopes utilise the stereoscopic approach, in which particle showers in the atmosphere are observed by several telescopes simultaneously, connected by a central trigger system at the hardware level. This approach greatly reduces the background of the instrument and thereby allows one to decrease the energy threshold and improve the sensitivity of the system. The functionality and performance of the central trigger of H.E.S.S., is presented. Making use of the reduced energy threshold and the improved sensitivity, a survey of the inner part of the Milky way in very high energy gamma-rays, was conducted in 2004 with H.E.S.S. at an unprecedented sensitivity level. The Galactic plane between +- 30deg, in longitude and +-3deg, in latitude relative to the Galactic centre was observed for a total of 230 hours, reaching an average flux sensitivity of 3% of the Crab nebula at energies above 200 GeV. Fourteen new sources were detected at a significance level greater than 4 sigma in addition to three previously known sources in this area. Detailed spectral and morphological information for these new sources are provided, along with a discussion on possible counterparts in other wavelength bands. The distribution in galactic latitude of the detected sources appears to be consistent with a scale height in the galactic disc for the parent population of less than 100 parsec.