Instituut-Lorentz for Theoretical Physics, Universiteit Leiden, Niels Bohrweg 2, 2333 CA Leiden, Netherlands.
Ecole Polytechnique Fédérale de Lausanne, FSB/ITP/LPPC, BSP, CH-1015 Lausanne, Switzerland.
Phys Rev Lett. 2014 Dec 19;113(25):251301. doi: 10.1103/PhysRevLett.113.251301. Epub 2014 Dec 15.
We report a weak line at 3.52±0.02 keV in x-ray spectra of the Andromeda galaxy and the Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and p-n (PN) CCD cameras of the XMM-Newton telescope. This line is not known as an atomic line in the spectra of galaxies or clusters. It becomes stronger towards the centers of the objects; is stronger for Perseus than for M31; is absent in the spectrum of a deep "blank sky" data set. Although for each object it is hard to exclude that the feature is due to an instrumental effect or an atomic line, it is consistent with the behavior of a dark matter decay line. Future (non-)detections of this line in multiple objects may help to reveal its nature.
我们在 X 射线卫星（XMM-Newton 望远镜）的金属氧化物硅（MOS）和 p-n（PN）CCD 相机观测到的仙女座星系和英仙座星系团的 X 射线能谱中，发现了一个在 3.52±0.02keV 左右的微弱谱线。这条谱线在星系或星系团的光谱中，不属于任何已知原子谱线。这条谱线在物体中心附近较强，在英仙座星系团中比在仙女座星系中更强，在一个深度“空白天空”数据集的光谱中则不存在。尽管对于每个物体来说，很难排除该谱线是仪器效应或原子谱线造成的，但它与暗物质衰变线的行为一致。未来在多个物体中对这条谱线的（非）探测，可能有助于揭示其性质。
