collaborators

6 papers

astro-ph.GA2026

DeepDive: Simultaneous Formation of Massive Quiescent Galaxies in High-Redshift Galaxy Proto-clusters

Takumi Kakimoto, Masayuki Tanaka, Kei Ito +19

We report on the spectroscopic confirmation of overdense regions of massive quiescent galaxies (QGs) in the early Universe with JWST/NIRSpec. Based on data from the DeepDive NIRSpe…

astro-ph.GA2026

The role of small-scale environments in the quenching of massive galaxies at

Takumi Kakimoto, Masayuki Tanaka, Makoto Ando +10

Massive quiescent galaxies (QGs) at high redshifts are likely progenitors of massive elliptical galaxies in the local Universe. Recent observations, such as the discovery of QGs in…

astro-ph.GA2025

Merger fraction in galaxy groups and clusters at z < 0.2: A non-parametric morphological study with Subaru Hyper Suprime-Cam

Anri Yanagawa, Yoshiki Toba, Naomi Ota +7

We investigate the environmental dependence of galaxy mergers using high-resolution imaging data from the Hyper Suprime-Cam (HSC) Subaru Strategic Program. We focus on galaxy group…

astro-ph.GA2025

The COSMOS-Web deep galaxy group catalog up to

Greta Toni, Ghassem Gozaliasl, Matteo Maturi +41

Galaxy groups with and up to a few tens of members are the most common galaxy environment, marking the transition between field and massive clu…

astro-ph.GA2025

Cluster candidates with massive quiescent galaxies at

Tomokazu Kiyota, Makoto Ando, Masayuki Tanaka +7

Galaxy clusters are crucial to understanding role of the environment in galaxy evolution. However, due to their rarity, only a limited number of clusters have been identified at $z…

astro-ph.GA2025

Cosmic Himalayas: The Highest Quasar Density Peak Identified in a 10,000 deg Sky with Spatial Discrepancies between Galaxies, Quasars, and IGM HI

Yongming Liang, Masami Ouchi, Dongsheng Sun +27

We report the identification of a quasar overdensity in the BOSSJ0210 field, dubbed Cosmic Himalayas, consisting of 11 quasars at , the densest overdensity of quasars…