15 papers
Gas-Phase Metallicity and Nitrogen Abundances in Low-Mass Galaxies Down to at -- from JWST Lensing Cluster Surveys
Hiroya Umeda, Masami Ouchi, Kimihiko Nakajima +7
We analyze 405 deep JWST/NIRSpec spectra of star-forming galaxies at -- from DREAMS and other lensing-cluster surveys to study chemical enrichment in intrinsically fai…
An Ultra-Faint, Chemically Primitive Galaxy Forming in the Reionization Era
Kimihiko Nakajima, Masami Ouchi, Yuichi Harikane +9
The formation of the first stars and galaxies marked the onset of chemical enrichment, yet direct observations of such primordial systems remain elusive. Here we present James Webb…
A UV-Luminous Galaxy at z=11 with Surprisingly Weak Star Formation Activity
Yuichi Harikane, Pablo G. Perez-Gonzalez, Javier Alvarez-Marquez +8
One of the major discoveries by the James Webb Space Telescope (JWST) is the identification of a large population of luminous galaxies at , challenging theoretical models for…
A New Constraint on the Optical Depth from the Reionization History Independent of CMB Large-Scale E-Mode Polarization
Yuta Kageura, Masami Ouchi, Fumihiro Naokawa +5
Recent studies report a mild discrepancy between BAO and CMB measurements within the CDM framework. This discrepancy could be explained if the optical depth inferred from…
VENUS: Two Faint Little Red Dots Separated by Hidden in a Single Lensed Galaxy at
Hiroto Yanagisawa, Masami Ouchi, Miriam Golubchik +47
We report the identification of a pair of faint little red dots (LRDs), dubbed Red Eyes, in a strongly-lensed galaxy at behind the PLCKG004.5-10.5 cluster, identified from…
Probing the Cosmic Reionization History with JWST: Gunn-Peterson and Ly Damping Wing Absorption at
Hiroya Umeda, Masami Ouchi, Yuta Kageura +4
We present a statistical analysis of Ly absorption using 581 galaxies at --13 observed with multiple JWST/NIRSpec spectroscopy programs, including JADES, UNCOVER, CEERS,…