Early results of the Hitomi Satellite
Hitomi is the 6th Japanese X-ray astronomical satellite developed with international collaborations. The X-ray micro-calorimeter on board Hitomi has a unique capability that it can measure the energy of X-ray photons very precisely even coming from spatially extended objects such as clusters of galaxies; before Hitomi it was required to use gratings to obtain energy resolution comparable to Hitomi, and thus precise X-ray spectroscopy was impossible for the spatially extended objects. Hitomi also carries Hard X-ray Telescopes developed by Nagoya Univ. that can focus X-rays with an energy up to 80 keV. Although Hitomi was launched successfully in Feb 17, 2016, the communication with the satellite was lost on Mar. 26, 2016 due to several troubles including an operation mistake, and then the operation was stopped on Apr. 28., 2016. However, Hitomi observed a few targets before the loss of the communication. One of the objects is the Perseus cluster of galaxies, and the first results of the observation was already published in Nature 535, 117, 2016. In this KMI topics, I try to explain the capabilities of Hitomi and its early results including the Perseus cluster for those who are not experts in astronomy.