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Hitomi (ASTRO-H) carries two Hard X-ray Telescopes (HXTs) that can focusX-rays up to 80 keV. Combined with the Hard X-ray Imagers (HXIs) that detectthe focused X-rays, imaging spectroscopy in the high-energy band from 5 keV to80 keV is made possible. We studied characteristics of HXTs after the launchsuch as the encircled energy function (EEF) and the effective area using thedata of a Crab observation. The half power diameters (HPDs) in the 5--80 keVband evaluated from the EEFs are 1.59 arcmin for HXT-1 and 1.65 arcmin forHXT-2. Those are consistent with the HPDs measured with ground experiments whenuncertainties are taken into account. We can conclude that there is nosignificant change in the characteristics of the HXTs before and after thelaunch. The off-axis angle of the aim point from the optical axis is evaluatedto be less than 0.5 arcmin for both HXT-1 and HXT-2. The best-fit parametersfor the Crab spectrum obtained with the HXT-HXI system are consistent with thecanonical values.

Inorbit Performance of the Hard X-ray Telescope (HXT) on board the Hitomi (ASTRO-H) satellite