Lee Samuel K, Lisanti Mariangela, Safdi Benjamin R, Slatyer Tracy R, Xue Wei
Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA.
Broad Institute, Cambridge, Massachusetts 02142, USA.
Phys Rev Lett. 2016 Feb 5;116(5):051103. doi: 10.1103/PhysRevLett.116.051103. Epub 2016 Feb 4.
We present a new method to characterize unresolved point sources (PSs) generalizing traditional template fits to account for non-Poissonian photon statistics. We apply this method to Fermi Large Area Telescope γ-ray data to characterize PS populations at high latitudes and in the Inner Galaxy. We find that PSs (resolved and unresolved) account for ∼50% of the total extragalactic γ-ray background in the energy range ∼1.9 to 11.9 GeV. Within 10° of the Galactic Center with |b|≥2°, we find that ∼5%-10% of the flux can be accounted for by a population of unresolved PSs distributed consistently with the observed ∼GeV γ-ray excess in this region. The excess is fully absorbed by such a population, in preference to dark-matter annihilation. The inferred source population is dominated by near-threshold sources, which may be detectable in future searches.
我们提出了一种新方法来表征未解析的点源（PSs），该方法推广了传统的模板拟合，以考虑非泊松光子统计。我们将此方法应用于费米大面积望远镜的γ射线数据，以表征高纬度和银河系内部的PS群体。我们发现，在能量范围约1.9至11.9 GeV内，PSs（已解析和未解析的）约占总河外γ射线背景的50%。在银心10°范围内且|b|≥2°时，我们发现约5%-10%的通量可由一群未解析的PSs贡献，其分布与该区域观测到的约GeV γ射线过剩一致。这种过剩完全可由这样一群源吸收，而不是暗物质湮灭。推断出的源群体以近阈值源为主，未来搜索中可能可探测到。
