Foster Joshua W, Kongsore Marius, Dessert Christopher, Park Yujin, Rodd Nicholas L, Cranmer Kyle, Safdi Benjamin R
Leinweber Center for Theoretical Physics, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Berkeley Center for Theoretical Physics, University of California, Berkeley, California 94720, USA.
Phys Rev Lett. 2021 Jul 30;127(5):051101. doi: 10.1103/PhysRevLett.127.051101.
Sterile neutrinos with masses in the keV range are well-motivated extensions to the Standard Model that could explain the observed neutrino masses while also making up the dark matter (DM) of the universe. If sterile neutrinos are DM then they may slowly decay into active neutrinos and photons, giving rise to the possibility of their detection through narrow spectral features in astrophysical x-ray data sets. In this Letter, we perform the most sensitive search to date for this and other decaying DM scenarios across the mass range from 5 to 16 keV using archival XMM-Newton data. We reduce 547 Ms of data from both the MOS and PN instruments using observations taken across the full sky and then use this data to search for evidence of DM decay in the ambient halo of the Milky Way. We determine the instrumental and astrophysical baselines with data taken far away from the Galactic Center, and use Gaussian process modeling to capture additional continuum background contributions. No evidence is found for unassociated x-ray lines, leading us to produce the strongest constraints to date on decaying DM in this mass range.
质量处于keV范围的 sterile中微子是标准模型合理的扩展，它可以解释观测到的中微子质量，同时也构成宇宙的暗物质（DM）。如果sterile中微子是暗物质，那么它们可能会缓慢衰变为活性中微子和光子，从而有可能通过天体物理X射线数据集中的窄谱特征来探测它们。在这篇快报中，我们利用存档的XMM-牛顿数据，对5至16 keV质量范围内的这种以及其他衰变暗物质情形进行了迄今为止最灵敏的搜索。我们使用全天空的观测数据，对MOS和PN仪器的547 Ms数据进行了缩减，然后用这些数据搜索银河系周围晕圈中暗物质衰变的证据。我们用远离银心的数据确定了仪器和天体物理基线，并使用高斯过程建模来捕捉额外的连续背景贡献。未发现与X射线线无关的证据，这使我们对该质量范围内衰变暗物质产生了迄今为止最强的限制。
