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arXiv 1802.05258astro-ph.HEastro-ph.COhep-ph
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湮灭暗物质作为M31发射Gamma-Ray起源的多波长分析

A Multi-Wavelength Analysis of Annihilating Dark Matter as the Origin of the Gamma-Ray Emission from M31

Alex McDaniel, Tesla Jeltema, Stefano Profumo

摘要:

[摘要]通过多波长天文观测间接探测暗物质(DM)为探测DM的粒子性质提供了一条有前途的途径。在由弱相互作用大质量粒子(WIMPs)组成的DM的情况下,自湮灭最终产生可观测的产物,包括$e^{\pm}$对和伽马射线。伽马射线可以直接探测到,而$e^{\pm}$对可以通过来自同步辐射的无线电发射或X射线和来自逆康普顿散射的软伽马射线来探测。寻找DM天体物理学迹象的一个有趣区域是银河系的银河系中心(GC),部分原因是观测到的可能是DM的伽马射线过量。费米-LAT合作最近在仙女座星系(M31)中心区域观察到类似的过量,这使我们探索DM诱导信号的可能性。我们使用RX-DMFIT工具对M31中潜在的DM湮灭发射进行多频分析。我们认为WIMP模型与GC过量一致,并与M31的观测数据进行比较,计算了整个电磁频谱的预期发射。我们发现,最适合M31过剩的粒子模型有利于较低的质量比GC过剩。最佳拟合模型是$b\bar{b}$终态的$M_χ=11$ GeV和$\left<σv\right>=2.6\times 10^{-26}$ cm $^3$ s $^{-1}$,以及均匀混合的$b\bar{b}/τ^+τ^-$终态的$M_χ=5.8$ GeV和$\left<σv\right>=2.03\times 10^{-26}$ cm $^3$ s $^{-1}$。对于保守估计的扩散和磁场模型,预期的无线电发射似乎与M31中心区域目前可用的数据处于紧张状态,尽管这种约束对描述磁场强度和几何形状的参数选择值有相当强的依赖性。

英文摘要:

[Abridged] Indirect detection of dark matter (DM) by multi-wavelength astronomical observations provides a promising avenue for probing the particle nature of DM. In the case of DM consisting of Weakly-Interacting Massive Particles (WIMPs), self-annihilation ultimately produces observable products including $e^{\pm}$ pairs and gamma rays. The gamma rays can be detected directly, while the $e^{\pm}$ pairs can be detected by radio emission from synchrotron radiation or X-rays and soft gamma rays from inverse Compton scattering. An intriguing region to search for astrophysical signs of DM is the Galactic center (GC) of the Milky Way, due in part to an observed excess of gamma-rays that could be DM. A recent observation by the Fermi-LAT collaboration of a similar excess in the central region of the Andromeda galaxy (M31) leads us to explore the possibility of a DM-induced signal there as well. We use the RX-DMFIT tool to perform a multi-frequency analysis of potential DM annihilation emissions in M31. We consider WIMP models consistent with the GC excess and calculate the expected emission across the electromagnetic spectrum in comparison with available observational data from M31. We find that the particle models that best fit the M31 excess favor lower masses than the GC excess. The best fitting models are for a $b\bar{b}$ final state with $M_χ=11$ GeV and $\left<σv\right>=2.6\times 10^{-26}$ cm$^3$s$^{-1}$, as well as an evenly mixed $b\bar{b}/τ^+τ^-$ final state with $M_χ=5.8$ GeV and $\left<σv\right>=2.03\times 10^{-26}$ cm$^3$s$^{-1}$. For conservative estimates of the diffusion and magnetic field models the expected radio emissions appear to be in tension with currently available data in the central region of M31, although this constraint has a fairly strong dependence on the values chosen for parameters describing the magnetic field strength and geometry.

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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