Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster
Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster
High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E=3.5 keV emission line reported in several low-resolution studies of various massive systems, such as galaxies and clusters, including the Perseus cluster. We have analyzed the Hitomi first-light observation of the Perseus cluster. The emission …