http://arxiv.org/abs/1412.1869
We present the results from deep Suzaku observations of the central region of the Perseus cluster. Bulbul et al. (2014) reported the detection by XMM-Newton instruments of an unidentified X-ray emission line at an energy around 3.5keV in spectra for the Perseus and other clusters. They argued for a possibility of the decay of sterile neutrino, a dark matter candidate. We examine Suzaku X-ray Imaging Spectrometer (XIS) spectra of the Perseus cluster for evidence in the 3.5keV line and other possible dark matter features in the 2-6keV energy band. In order to search for and constrain a weak line feature with the XIS, observations of the Crab nebula are used to evaluate the system’s effective area. We found no line feature at the claimed position with a systematic line flux upper limit at a half (1.5eV in line equivalent width) of the claimed best-fit value by Bulbul et al. We discuss this inconsistency in terms of instrumental calibration errors and modeling of continuum emission. Future prospects for high-energy resolution spectroscopy with ASTRO-H are presented.
T. Tamura, R. Iizuka, Y. Maeda, et. al.
Mon, 8 Dec 14
47/61
Comments: Submitted to PASJ, 2014-11