activity
20242026
collaborators

20 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.CO2026

Double-Peaked Ly Emission during Reionization Requires Nearby Voids and a Favorable Local Ionizing Background

Hyunbae Park, Aaron Smith, Intae Jung +11

Several Lyman-alpha (Ly) emitters deep into the reionization era exhibit double-peaked Ly emission profiles, raising the question of how the intergalactic medium can transm…

astro-ph.GA2026

EMPRESS. XV. A New Determination of the Primordial Helium Abundance Suggesting a Moderately Low Value

Hiroto Yanagisawa, Masami Ouchi, Akinori Matsumoto +18

We present a new constraint on the primordial helium abundance, , based on Subaru observations. A major source of uncertainty in previous determination…

astro-ph.GA2026

ATT12: The Antarctic 12-m Terahertz Telescope for Studies of Dusty Galaxies. I. Instrument Sensitivity and Science Forecasts

Koki Wakasugi, Takuya Hashimoto, Nario Kuno +13

We present a feasibility study of the Antarctic 12m Terahertz Telescope (ATT12), a next-generation facility to be constructed at New Dome Fuji in Antarctica, designed to open up th…

astro-ph.GA2026

JWST Spectroscopic Census of ALMA Faint Submillimeter Galaxies in the Hubble Ultra Deep Field

Tomokazu Kiyota, Masami Ouchi, Daisuke Iono +6

We present a JWST/NIRSpec rest-frame optical spectroscopic census of ALMA 1-mm continuum sources in the Hubble Ultra Deep Field (UDF) identified by the deep ALMA UDF and ASPECS pro…