Oral Presentation

Spider-Webb: A sharp, complete picture of forming protocluster galaxies at z=2

Author(s): Yusei Koyama (NAOJ)

Presenter: Yusei Koyama (National Astronomical Observatory of Japan)

We present an overview of our recent intensive observing campaign targeting a rich protocluster at z=2.16 (so-called "Spiderweb" protocluster), with JWST, HST, ALMA, and Subaru, with the main goal to reveal the processes behind the formation and evolution of massive quiescent elliptical galaxies in young cluster environment. Our panoramic narrow-band H-alpha imaging with Subaru/MOIRCS, in combination with the deep HST/WFC3 slitless spectroscopy successfully map the large-scale structures around the protocluster traced by both star-forming and quiescent galaxies - and subsequently, our recent JWST/NIRCam follow-up observations revealed, for the first time, the stellar mass distribution within the galaxies in the rest-frame NIR, demonstrating a non-negligible fraction of protocluster galaxies already exhibiting elliptical morphology at this high redshift. After highlighting important outcomes from this "Spider-Webb" program, we will also present the current status of the "ULTIMATE-Subaru" project, a key instrumentation program of the Subaru Telescope, to develop a wide-field adaptive optics (GLAO) system and a new wide-field NIR camera (WFI). ULTIMATE-Subaru will deliver a high-quality, GLAO-assisted (FWHM~0.2 arcsec) image over ~14'x14' FoV. We want to discuss the potential impact on cluster/protocluster science of ULTIMATE, with its improved image quality, sensitivity, and a unique set of narrow-band (NB) and medium-band (MB) filters.