Subaru Telescope | National Astronomical Observatory of Japan | 2017 Mar 29
[c][attachment=0]fig1e_s[1].png[/attachment][/c][hr][/hr]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. (Figure 1). 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.
“We are surprised because the dense gas structure is extended much more than expected in the proto-supercluster,” said Dr. Mawatari. “Wider field observations with narrow-band filters are needed to grasp full picture of this largest structure in the young universe. This is exactly the type of strong research that can be done with Hyper Suprime-Cam (HSC) recently mounted at the Subaru Telescope. We intend to study the gas-galaxy relation in various proto-superclusters using the HSC.”
Stars assembled to form galaxies, and galaxies are clustered to form larger structures such as clusters or superclusters. Matter in the current universe is structured in a hierarchical manner on scales of ~ 100 million light-years. However, we cannot observe inhomogeneous structure in any direction or distance over scales larger than that. One important issue in modern astronomy is to clarify how perfectly the large-scale uniformity and homogeneity in matter distribution is maintained. In addition, astronomers seek to investigate the properties of the seeds of large-scale structures (i.e., the initial matter fluctuations) that existed at the beginning of the universe. Thus, it is important to observe huge structures at various epochs (which translates to distances). The study of gaseous matter as well as galaxies is needed for an accurate and comprehensive understanding. This is because local superclusters are known to be rich in gas. Furthermore, it is clear that there are many newborn galaxies in ancient (or distant) clusters. A detailed comparison between the spatial distributions of galaxies and gas during the early epochs of the universe is very important to understand process of galaxy formation from the dim (low light-emitting) clumps of gas in the early universe. ...
Imaging of Diffuse HI Absorption Structure in the SSA22 Protocluster Region at z = 3.1 - Ken Mawatari et al
- Monthly Notices of the RAS 467(4):3951 (June 2017) DOI: 10.1093/mnras/stx038
arXiv.org > astro-ph > arXiv:1701.02462 > 10 Jan 2017