DISCOVERY OF GeV γ-RAY EMISSION FROM PSR B1259−63/LS 2883
DISCOVERY OF GeV γ-RAY EMISSION FROM PSR B1259−63/LS 2883
复制标题
DOI：
10.1088/2041-8205/736/1/l10
复制
发表时间：
2011-03
期刊：
影响因子：
--
通讯作者：
P. Tam;Regina H. H. Huang-Regina-H.-H.-Huang-49753021;J. Takata;C. Hui;A. Kong;K. Cheng
中科院分区：
文献类型：
--
作者：
P. Tam;Regina H. H. Huang-Regina-H.-H.-Huang-49753021;J. Takata;C. Hui;A. Kong;K. Cheng
双星系统PSRB1259−63/LS2883由一颗47.8ms射电脉冲星组成，它在高度偏心的轨道上以3.4年的周期绕伴星Be运行。该系统已经在无线电、X射线和TeVγ-射线频段进行了良好的采样，并在所有观测频率上显示出轨道相变。在这里，我们报告了从PSRB1259γ63/LS2883到2010年的近星通道中发现的>；100 MeV−射线。利用费米星上的大面积望远镜收集的数据，从绕星前33天到绕星后75天，检测到PSRB1259−63/LS2883，其标准差为13.6%。γ光线曲线在这段时间内变化很大，光子指数的变化与γ光线流量相关。特别是，观测到了近星通过后发生的两个主要耀斑。γ射线发射的开始时间与发生在近星粒子通过之前1个月和之后1个月的∼和∼的两个盘通道接近，但不是在相同的轨道位相上。GeV轨道光曲线不同于X射线和TeV光曲线，这一事实有力地表明GeVγ射线发射来自不同的成分。我们推测观测到的GeV耀斑可能是由多普勒增强效应引起的。
The binary system PSR B1259−63/LS 2883 consists of a 47.8 ms radio pulsar that orbits the companion Be star with a period of 3.4 years in a highly eccentric orbit. The system has been well sampled in radio, X-ray, and TeV γ-ray bands, and shows orbital phase-dependent variability in all observed frequencies. Here we report on the discovery of >100 MeV γ-rays from PSR B1259−63/LS 2883 through the 2010 periastron passage. Using data collected with the Large Area Telescope on board Fermi from 33 days before periastron to 75 days after periastron, PSR B1259−63/LS 2883 was detected at a significance of 13.6 standard deviations. The γ-ray light curve was highly variable over this period, with a changing photon index that correlates with the γ-ray flux. In particular, two major flares that occur after the periastron passage were observed. The onset of γ-ray emission occurs close to, but not at the same orbital phases as, the two disk passages that occur ∼1 month before and ∼1 month after the periastron passage. The fact that the GeV orbital light curve is different from that of the X-ray and TeV light curves strongly suggests that GeV γ-ray emission originates from a different component. We speculate that the observed GeV flares may be resulting from Doppler boosting effects.