Rationale

Exploring the early Universe is one of the major goals of modern astronomy and astrophysics. The James Webb Space Telescope (JWST) is now routinely providing a wealth of innovative observations, including the discovery of bright star-forming galaxies beyond the cosmological redshift of z=10, an unexpectedly large population of active galactic nuclei powered by supermassive blackholes, and quiescent galaxies even within the first 1 Gyr of the cosmic time. Although the JWST has super high sensitivity, its field-of-view is still too narrow to conduct >>1 degree2 imaging surveys that require finding rare, massive, bright galaxies in the early Universe. The European Euclid satellite is now conducting its super wide-field surveys, but it is limited to a wavelength less than 2 micron. NASA’s Roman telescope to be launched in 2026 also has the same wavelength limitation. Since the Lyman alpha break comes to >2 micron for galaxies at z>15, when the most exciting event, the first galaxy formation happened. The Japanese space telescope concept, GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) will provide the unique capability of wide-field imaging at a wavelength range of 2 to 8 micron in the mid-2030s.

This 2-day meeting aims to discuss the JWST’s groundbreaking results for galaxy formation studies and how to fully unlock the potential of GREX-PLUS wide-field imaging surveys in the mid-2030s.

Organizers

Akio Inoue (Waseda U.), Issei Yamamura (ISAS/JAXA), Takao Nakagawa (ISAS/JAXA), Yuma Sugahara (Waseda U.), Jean-Louis Moortgat (Waseda Brussels Office)