Fermi LAT Search for Internal Bremsstrahlung Signatures from Dark Matter Annihilation
Fermi LAT Search for Internal Bremsstrahlung Signatures from Dark Matter Annihilation
复制标题
DOI：
10.1088/1475-7516/2012/07/054
复制
发表时间：
2012-03
影响因子：
6.4
通讯作者：
T. Bringmann;Xiaoyuan Huang;A. Ibarra;S. Vogl;C. Weniger
中科院分区：
文献类型：
--
作者：
T. Bringmann;Xiaoyuan Huang;A. Ibarra;S. Vogl;C. Weniger
在间接寻找银河系暗物质的过程中，一个经常遇到的障碍是如何从天体物理背景中分离出可能的信号。考虑到这些信号很可能是次显性的，寻找明显的光谱特征在间接探测实验中起着关键作用;单色伽马射线线或与内部韧致辐射相关的类似特征，特别是，提供了确凿的特征。我们执行一个专门的搜索后者在费米伽马射线太空望远镜在其头43个月的数据。为此，我们使用一个新的自适应程序来选择最佳的目标区域，同时考虑到标准和收缩的暗物质配置文件。我们的统计方法的行为进行了测试，通过对全天空数据的子采样分析，发现再现理论预期非常好。我们得到的暗物质湮灭截面的限制比从矮星系的观测中得到的要强，至少对于这里考虑的模型，对撞机搜索。虽然这些极限仍然不足以探测热产生暗物质的湮灭率，但未来这样做的前景非常好。事实上，我们已经发现了一个微弱的迹象，当（不）考虑到别处效应时，其显著性为3.1σ（4.3σ），对应于暗物质质量约为150 GeV的内部韧致辐射信号;同样的信号也很好地拟合了大约130 GeV的伽马射线线。虽然这是一个令人着迷的可能性，但我们警告说，需要进行更专门的分析和更多的数据来排除或确认这一选择。
A commonly encountered obstacle in indirect searches for galactic dark matter is how to disentangle possible signals from astrophysical backgrounds. Given that such signals are most likely subdominant, the search for pronounced spectral features plays a key role for indirect detection experiments; monochromatic gamma-ray lines or similar features related to internal bremsstrahlung, in particular, provide smoking gun signatures. We perform a dedicated search for the latter in the data taken by the Fermi gamma-ray space telescope during its first 43 months. To this end, we use a new adaptive procedure to select optimal target regions that takes into account both standard and contracted dark matter profiles. The behaviour of our statistical method is tested by a subsampling analysis of the full sky data and found to reproduce the theoretical expectations very well. The limits on the dark matter annihilation cross-section that we derive are stronger than what can be obtained from the observation of dwarf galaxies and, at least for the model considered here, collider searches. While these limits are still not quite strong enough to probe annihilation rates expected for thermally produced dark matter, future prospects to do so are very good. In fact, we already find a weak indication, with a significance of 3.1σ (4.3σ) when (not) taking into account the look-elsewhere effect, for an internal bremsstrahlung-like signal that would correspond to a dark matter mass of ~150 GeV; the same signal is also well fitted by a gamma-ray line at around 130 GeV. Although this would be a fascinating possibility, we caution that a much more dedicated analysis and additional data will be necessary to rule out or confirm this option.