NuSTAR tests of sterile-neutrino dark matter: New Galactic bulge observations and combined impact
NuSTAR tests of sterile-neutrino dark matter: New Galactic bulge observations and combined impact
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DOI：
10.1103/physrevd.101.103011
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发表时间：
2019-08
影响因子：
5
通讯作者：
B. Roach;K. Ng;K. Perez;J. Beacom;S. Horiuchi;R. Krivonos;D. Wik
中科院分区：
文献类型：
--
作者：
B. Roach;K. Ng;K. Perez;J. Beacom;S. Horiuchi;R. Krivonos;D. Wik
我们分析了两个专门的NuSTAR观测，其中190$ks位于距离银河系平面10^\ciRC的地方，一个在上面，另一个在下面，以寻找来自稀有中微子暗物质辐射衰变的x射线。选择这些区域是为了最小化天体物理x射线背景，同时保持在暗物质晕最密集的区域附近。在5-20keV的能量范围内，我们没有发现对应于稀有中微子质量为10-40keV的反常x射线的证据。在中微子混合产生的稀薄中微子的背景下解释，这些观测提供了质量在10-12keV范围内的主要约束，比以前在这个范围内的约束提高了2倍。我们还将我们的结果与蒙特卡罗模拟进行了比较，结果表明，我们导出的极限的波动并不是由系统效应主导的。目前正在开发的仪器背景更新模型将提高NuSTAR对异常X射线线的敏感性，特别是对能量为3-5keV的X射线线。
We analyze two dedicated NuSTAR observations with exposure ${\sim}190$ ks located ${\sim}10^\circ$ from the Galactic plane, one above and the other below, to search for x-ray lines from the radiative decay of sterile-neutrino dark matter. These fields were chosen to minimize astrophysical x-ray backgrounds while remaining near the densest region of the dark matter halo. We find no evidence of anomalous x-ray lines in the energy range 5--20 keV, corresponding to sterile neutrino masses 10--40 keV. Interpreted in the context of sterile neutrinos produced via neutrino mixing, these observations provide the leading constraints in the mass range 10--12 keV, improving upon previous constraints in this range by a factor ${\sim}2$. We also compare our results to Monte Carlo simulations, showing that the fluctuations in our derived limit are not dominated by systematic effects. An updated model of the instrumental background, which is currently under development, will improve NuSTAR's sensitivity to anomalous x-ray lines, particularly for energies 3--5 keV.