Discovery of a new extragalactic population of energetic particles
Discovery of a new extragalactic population of energetic particles
复制标题
发现新的河外高能粒子群
DOI：
10.1103/physrevd.95.063018
复制
发表时间：
2017
影响因子：
5
通讯作者：
Brown A
中科院分区：
文献类型：
--
作者：
Brown A
我们报告发现半人马座A（Cen A）核心的费米-LAT射线光谱在统计上显著硬化，光谱指数从到硬化，断裂能为。使用似然分析，我们发现没有证据表明通量变化在岑A的核心光变曲线以上或以下的光谱中断时，考虑到整个8年的时间。然而，有趣的是，第一个低能量光变曲线显示了在置信水平上通量变化的证据。为了理解这种光谱断裂的起源，我们假设断裂特征下方的低能分量来自半人马座A射电喷流中的轻子，我们研究了光谱断裂上方的高能分量是由于靠近Cen A核心的额外的非常高能量粒子源的可能性。我们首次表明，活动星系核的反射射线光谱与暗物质晕轮廓中的一个非常大的局部增强（称为尖峰）或毫秒星的人口是兼容的。我们的工作构成了第一个强有力的迹象，表明新射线产生机制可以解释活动星系的发射，并可以为黑洞周围的重暗物质粒子聚集提供诱人的第一个证据。
We report the discovery of a statistically significant hardening in theFermi-LAT-ray spectrum of Centaurus A’s (Cen A) core, with the spectral index hardening fromtoat a break energy of. Using a likelihood analysis, we find no evidence for flux variability in Cen A’s core light curve above or below the spectral break when considering the entire 8 year period. Interestingly, however, the firstof the low energy light curve shows evidence of flux variability at theconfidence level. To understand the origin of this spectral break, we assume that the low energy component below the break feature originates from leptons in Centaurus A’s radio jet, and we investigate the possibility that the high energy component above the spectral break is due to an additional source of very high energy particles near the core of Cen A. We show for the first time that the observed-ray spectrum of an active galactic nucleus is compatible with either a very large localized enhancement (referred to as a spike) in the dark matter halo profile or a population of millisecond pulsars. Our work constitutes the first robust indication that new-ray production mechanisms can explain the emission from active galaxies and could provide tantalizing first evidence for the clustering of heavy dark matter particles around black holes.