Zhong Yi-Ming, McDermott Samuel D, Cholis Ilias, Fox Patrick J
Kavli Institute for Cosmological Physics, University of Chicago, Chicago, Illinois 60637, USA.
Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
Phys Rev Lett. 2020 Jun 12;124(23):231103. doi: 10.1103/PhysRevLett.124.231103.
The Fermi Large Area Telescope (Fermi-LAT) Collaboration has an updated point source catalog, referred to as 4FGL. We perform the first template fit using a mask based on this new catalog and find that the excess in gamma rays detected at the Galactic Center in Fermi-LAT data persists. On the other hand, we find that a search for point sources is highly sensitive to the use of the 4FGL catalog: no sizable excess of bright pixels is apparent in the inner Galaxy when we mask out 4FGL point sources. Combining these observations restricts the ability of point sources to contribute to the Galactic Center excess. After identifying which bright sources have no known counterpart, we place strong constraints on any point source luminosity function capable of explaining the smooth emission identified in the template fit.
费米大面积望远镜（Fermi-LAT）合作组织有一个更新后的点源目录，称为4FGL。我们基于这个新目录使用掩模进行了首次模板拟合，发现费米-LAT数据中在银河系中心探测到的伽马射线过量现象仍然存在。另一方面，我们发现对点源的搜索对4FGL目录的使用高度敏感：当我们屏蔽掉4FGL点源时，在银河系内部没有明显的大量亮像素过量。综合这些观测结果限制了点源对银河系中心过量现象的贡献能力。在确定哪些亮源没有已知对应物之后，我们对任何能够解释模板拟合中识别出的平滑发射的点源光度函数施加了严格限制。
