Search Publications
Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster
Mukai, K.; Yamaguchi, H.; Koyama, K. +215 more
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 e…
Consistency of Hitomi, XMM-Newton, and Chandra 3.5 keV data from Perseus
Conlon, Joseph P.; Day, Francesca; Jennings, Nicholas +2 more
Hitomi observations of Perseus with the Soft X-ray Spectrometer (SXS) provide a high-resolution look at the 3.5 keV feature reported by multiple groups in the Perseus cluster. The Hitomi spectrum—which involves the sum of diffuse cluster emission and the pointlike central active galactic nucleus (AGN)—does not show any excess at E ∼3.5 keV , givin…
Outgas analysis of mechanical cryocoolers for long lifetime
Nakagawa, Takao; Mitsuda, Kazuhisa; Kanao, Kenichi +9 more
Mechanical cryocoolers for space applications are required to have high reliability to achieve long-term operation in orbit. ASTRO-H (Hitomi), the 6th Japanese X-ray astronomy mission, has a major scientific instrument onboard-the Soft X-ray Spectrometer (SXS) with several 20K-class two-stage Stirling (2ST) coolers and a 4K-class Joule Thomson (JT…
An analysis of the 2016 Hitomi breakup event
Flegel, Sven; Bennett, James; Lachut, Michael +2 more
The breakup of Hitomi (ASTRO-H) on 26 March 2016 is analysed. Debris from the fragmentation is used to estimate the time of the event by propagating backwards and estimating the close approach with the parent object. Based on this method, the breakup event is predicted to have occurred at approximately 01:42 UTC on 26 March 2016. The Gaussian vari…
Astronomical imaging with the X-ray observatory Hitomi
Nakajima, Hiroshi; Hitomi Collaboration
We report an imaging capability of the Japan-led X-ray observatory Hitomi, formerly known as ASTRO-H. It carries four scientific instruments of Soft X-ray Imager (SXI: CCD camera), Hard X-ray Imager (HXI), Soft X-ray Spectrometer, and Soft Gamma-ray Detector, allowing us to perform a wide-band high-sensitive imaging spectroscopy. We highlight the …