论文标题

神秘的银河中心过剩:虚假的点源和信号不施加不合格

The Enigmatic Galactic Center Excess: Spurious Point Sources and Signal Mismodeling

论文作者

Leane, Rebecca K., Slatyer, Tracy R.

论文摘要

银河中心GEV过量(GCE)引起了极大的兴趣,可能是暗物质歼灭或一些新型的天体物理现象,例如新的伽马射线发射脉冲星。在同伴论文中,我们表明,在银河中心周围的$ 10^\ Circ $ Radius区域(ROI)中,明显的证据证明了非波斯顿模板拟合(NPTF)的GCE点源(PSS)实际上是GCE的未修饰的南北不对称的工件。在这项工作中,我们开发了简化的分析描述,说明信号不键模型如何使PS人群明显偏爱,并证明了伴侣论文中指出的行为如何也出现在简单的模拟数据集中,这些数据集根本不包含PS信号。我们在实际伽马射线数据中探讨了这种行为的普遍性,并讨论了使用NPTF技术对过去和未来研究的含义。虽然一旦包括南北不对称的PS偏好下降并不普遍于大的ROI中,但我们表明,任何过分rig的信号模型都有预计会产生一个非常令人信服的虚假PS信号:显然显然具有显而易见的意义,并且显然具有可比性的意义,并且可以从真实的PS人群中表现出一定的范围,并且在分析方面表现出非常稳定的范围,并且在分析方面表现出了范围,并且是在分析中的范围,并且可以在分析方面表现出一致性的范围。 GCE PS人群。这与先前研究的系统不种中的形式形成对比,这些形式不太可能以相同的方式模仿PS人群。鉴于这一观察结果及其在GCE最亮的区域的明确实现,我们认为GCE的主要平滑起源与现有的NPTF分析并不紧张。

The Galactic Center GeV excess (GCE) has garnered great interest as a possible signal of either dark matter annihilation or some novel astrophysical phenomenon, such as a new population of gamma-ray emitting pulsars. In a companion paper, we showed that in a $10^\circ$ radius region of interest (ROI) surrounding the Galactic Center, apparent evidence for GCE point sources (PSs) from non-Poissonian template fitting (NPTF) is actually an artifact of unmodeled north-south asymmetry of the GCE. In this work, we develop a simplified analytic description of how signal mismodeling can drive an apparent preference for a PS population, and demonstrate how the behavior pointed out in the companion paper also appears in simpler simulated datasets that contain no PS signals at all. We explore the generality of this behavior in the real gamma-ray data, and discuss the implications for past and future studies using NPTF techniques. While the drop in PS preference once north-south asymmetry is included is not ubiquitous in larger ROIs, we show that any overly-rigid signal model is expected to yield a spurious PS signal that can appear very convincing: as well as apparent significance comparable to what one would expect from a true PS population, the signal can exhibit stability against a range of variations in the analysis, and a source count function that is very consistent with previous apparent NPTF-based detections of a GCE PS population. This contrasts with previously-studied forms of systematic mismodeling which are unlikely to mimic a PS population in the same way. In the light of this observation, and its explicit realization in the region where the GCE is brightest, we argue that a dominantly smooth origin for the GCE is not in tension with existing NPTF analyses.

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