arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1402.6703astro-ph.HEastro-ph.COastro-ph.GAhep-phhep-th
收藏

来自中心Milky Way的Gamma-Ray信号的特征:一个湮灭暗物质的令人信服的例子

The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter

Tansu Daylan, Douglas P. Finkbeiner, Dan Hooper, Tim Linden, Stephen K. N. Portillo, Nicholas L. Rodd, Tracy R. Slatyer

摘要:

过去的研究已经确定了从银河系中心周围区域的$\sim$ 1-3 GeV伽马射线的空间扩展过量,与预期的湮灭暗物质的发射一致。我们重新审视和仔细检查这个信号,目的是进一步限制其特征和起源。通过对\textit{Fermi}事件参数CTBCORE应用切割,我们抑制了点扩散函数的尾部,并生成高分辨率的伽马射线图,使我们能够更容易地分离各种伽马射线分量。在这些地图中,我们发现的GeV过剩是强大的,高度统计显着的,与光谱,角分布,和整体归一化,是在很好的协议,由简单的湮灭暗物质模型预测。例如,该信号非常好地拟合了36-51 GeV的暗物质粒子湮灭为$b\bar{b}$,其湮灭截面为$σv = (1-3)\times 10^{-26}$ cm $^3$ /s(归一化为0.4 GeV/cm $^3$的局部暗物质密度)。此外,我们确认的角度分布的过剩是近似球对称的,并围绕银河系的动力中心(在$\sim$ $0.05^{\circ}$的Sgr A $^*$)为中心,没有迹象表明沿银河系平面的伸长。观测到的信号至少从银河系中心延伸到$\simeq10^{\circ}$,这不支持这种发射来自毫秒级恒星的可能性。

英文摘要:

Past studies have identified a spatially extended excess of $\sim$1-3 GeV gamma rays from the region surrounding the Galactic Center, consistent with the emission expected from annihilating dark matter. We revisit and scrutinize this signal with the intention of further constraining its characteristics and origin. By applying cuts to the \textit{Fermi} event parameter CTBCORE, we suppress the tails of the point spread function and generate high resolution gamma-ray maps, enabling us to more easily separate the various gamma-ray components. Within these maps, we find the GeV excess to be robust and highly statistically significant, with a spectrum, angular distribution, and overall normalization that is in good agreement with that predicted by simple annihilating dark matter models. For example, the signal is very well fit by a 36-51 GeV dark matter particle annihilating to $b\bar{b}$ with an annihilation cross section of $σv = (1-3)\times 10^{-26}$ cm$^3$/s (normalized to a local dark matter density of 0.4 GeV/cm$^3$). Furthermore, we confirm that the angular distribution of the excess is approximately spherically symmetric and centered around the dynamical center of the Milky Way (within $\sim$$0.05^{\circ}$ of Sgr A$^*$), showing no sign of elongation along the Galactic Plane. The signal is observed to extend to at least $\simeq10^{\circ}$ from the Galactic Center, disfavoring the possibility that this emission originates from millisecond pulsars.

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。

↑