[Institute of Space and Astronautical Science (ISAS)] Subaru Telescope Detects the Shadow of a Gas Cloud in an Ancient Proto-supercluster

The Subaru Telescope Suprime-Cam image used in this work. Neutral hydrogen gas distribution is superposed on the Subaru image. The red color indicates denser regions of the neutral hydrogen gas. Cyan squares correspond to member galaxies in the proto-supercluster, while objects without cyan squares are foreground galaxies and stars. The distribution of neutral hydrogen gas does not align perfectly with the galaxies. (c) Osaka Sangyo University / NAOJ

A team led by researchers from Osaka Sangyo University, with members from Tohoku University, Japan Aerospace Exploration Agency (JAXA) and others, has used the Suprime-Cam on the Subaru Telescope to create the most-extensive map of neutral hydrogen gas in the early universe. This cloud appears widely spread out across 160 million light-years in and around a structure called the proto-supercluster. It is the largest structure in the distant universe, and existed some 11.5 billion years ago. Such a huge gas cloud is extremely valuable for studying large-scale structure formation and the evolution of galaxies from gas in the early universe, and merits further investigation.

This research will be published in the journal of the British Royal Astronomical Society (Monthly Notices of the Royal Astronomical Society, publisher Oxford University Press) in its June, 2017 issue of the printed version (Mawatari et al. 2017, MNRAS, 467, 3951, “Imaging of diffuse HI absorption structure in the SSA22 protocluster region at z = 3.1 “).