Hitomi (ASTRO-H) is a joint project with JAXA (Japan Aerospace Exploration Agency) and NASA (National Aeronautics and Space Administration) as the principal partners. Led by Japan, it is a large-scale international collaboration, boasting the participation of 8 countries including the United States, the Netherlands, and Canada, with additional partnership by ESA (European Space Agency). After launch, proposals for observations will be accepted from all over the world. As the sole large-scale public X-ray observatory, Hitomi will offer over 10 years of data to the public, and is highly anticipated by researchers who wish to understand “the physics of the hot universe.”

Hitomi (ASTRO-H) observing time will be available for any scientist across the world, based upon proposal selection (Guest Observation), following the initial operation and the calibration observation (Phase 0) and the Hitomi Science Working Group observing time (Phase 1). Submitted proposals will be selected by a peer review and the selected proposals will be awarded observing time. All the data will be subjected to a proprietary period, and will thereafter be made available publicly along with analysis software. Hitomi data will be a worldwide asset that anyone can access.

The hardware team and the software team have been working together to understand characteristics of the science instruments and build the calibration database. In order to obtain enough calibration accuracy to archive the Hitomi science goals, the team has developed an algorithm to best utilize the database. In order to make the Hitomi data widely available to the community, the data format adopted is the world standard defined by NASA for easy access. In addition, the easy-to-use Hitomi software package will be made available for free, which will allow anyone to analyze the data.

Hitomi is open to scientists in any field outside the team. The project will be not only soliciting observation proposals, but also providing an analysis guide and a technical description document. Those documents will be updated regularly. A help-desk will also be open in several locations around the world. Hitomi users can ask questions about any aspect of the data analysis.