activity
20242026
collaborators

17 papers

astro-ph.GA2026

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…

astro-ph.GA2026

DREAMS. JWST Spectroscopy of a Galaxy with an ALMA Dust Continuum Detection: Early Dust, Very High , and a Multi-wavelength [OIII] Ratio Discrepancy

Kana Takechi, Masami Ouchi, Kimihiko Nakajima +10

We present a deep DREAMS JWST/NIRSpec MSA medium-grating spectrum of MACS0416-Y1, a galaxy at with the highest-redshift ALMA dust continuum detection to date, in order to…

astro-ph.GA2026

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…

astro-ph.HE2026

Nuclear Physics of X-ray Bursts

Yi Xu, Hendrik Schatz, Rita Lau +2

Thermonuclear X-ray bursts from the surface of accreting neutron stars are the most common astrophysical explosions in our galaxy. They provide a unique window into the physics of…

astro-ph.GA2026

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…

astro-ph.HE2026

A spectroscopically confirmed, strongly lensed, metal-poor Type II supernova at z = 5.13

David A. Coulter, Conor Larison, Justin D. R. Pierel +88

Observing supernovae (SNe) in the early Universe (z > 3) provides a window into how both galaxies and individual stars have evolved over cosmic time, yet a detailed study of high-r…