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arXiv 2511.03350hep-phastro-ph.HE
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类恒星银河系中心过剩对粒子暗物质提出挑战

Stellar-like Galactic center excess challenges particle dark matter

Sorbonne Université(索邦大学);Laboratoire de Physique Théorique et Hautes Énergies (LPTHE), CNRS(高能理论物理实验室,法国国家科学研究中心);LAPTh, CNRS(理论物理实验室,法国国家科学研究中心);Univ. of Nova Gorica(新戈里察大学);University of Torino(都灵大学);Istituto Nazionale di Fisica Nucleare(意大利国家核物理研究所)

Silvia Manconi, Christopher Eckner, Francesca Calore, Fiorenza Donato

AI总结:

研究银河系中心过剩现象对粒子暗物质研究的挑战,通过结合自适应模板拟合和光子计数统计方法,重新评估其作为暗物质搜索目标的潜力,给出湮灭截面上限,为相关研究提供了新的限制和参考。

摘要:

银河系中心可能承载着来自粒子暗物质的最大间接信号,在许多合理模型中,暗物质最终会产生伽马射线。然而,由于在GeV能量下天体物理背景上存在意外的伽马射线成分的证据(即所谓的银河系中心过剩,最初在费米大面积望远镜数据中发现),该区域在暗物质研究中常被忽视。虽然最初认为这暗示着GeV热遗迹,但最近的研究支持将其解释为银河系凸起中类似毫秒脉冲星的恒星群体。在此基础上,我们通过结合自适应模板拟合和光子计数统计方法,重新评估银河系中心作为通过伽马射线进行间接暗物质搜索的强大目标,同时最小化银河系漫射发射背景的建模误差。用包含暗物质信号和恒星凸起的混合模型对伽马射线数据进行拟合,通过提取湮灭截面的95%置信水平上限来量化弱标度暗物质粒子湮灭信号的空间,根据暗物质密度分布,对质量小于300 GeV的情况给出了严格限制,模拟数据测试支持了结果的稳健性。

英文摘要:

The Galactic Center (GC) is potentially hosting the largest indirect signal from particle dark matter (DM), which in many well-motivated models would produce gamma rays as their final states. However, this region has often been dismissed for DM studies because of the evidence for an unexpected gamma-ray component over astrophysical backgrounds at GeV energies, firstly discovered in the data of the \textit{Fermi} Large Area Telescope (LAT), the so-called Galactic Center Excess (GCE). While this was initially considered to hint at GeV thermal relics, recent work supports a GCE interpretation in terms of a stellar population of millisecond pulsar-like sources in the Galactic bulge. Building on this preference, we re-evaluate the GC as a powerful target for indirect DM searches via gamma rays. This is achieved by combining adaptive template fitting and photon-count statistical methods to assess the role of sub-threshold point sources in the observed \textit{Fermi}-LAT gamma-ray counts, while minimizing the mismodeling of Galactic diffuse emission backgrounds. In a fully self-consistent way, the gamma-ray data are fitted with a mixed model comprising a DM signal and a stellar bulge, both potentially contributing to the GCE. The space left for signals from weak-scale DM particle annihilations is quantified by extracting 95\% C.L. upper limits on the annihilation cross section, which, depending on the DM density profile, result in stringent limits for masses $\lesssim 300$ GeV. The robustness of our results is supported by tests on simulated data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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