3 citations · 8 across the 10 of their papers we have counts for
10 papers
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 th…
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…
EMPRESS. X. Spatially resolved mass-metallicity relation in extremely metal-poor galaxies: evidence of episodic star-formation fueled by a metal-poor gas infall
Kimihiko Nakajima, Masami Ouchi, Yuki Isobe +47
Using the Subaru/FOCAS IFU capability, we examine the spatially resolved relationships between gas-phase metallicity, stellar mass, and star-formation rate surface densities (Sigma…
SILVERRUSH. XIV. Lya Luminosity Functions and Angular Correlation Functions from ~20,000 Lya Emitters at z~2.2-7.3 from upto 24 HSC-SSP and CHORUS Surveys: Linking the Post-Reionization Epoch to the Heart of Reionization
Hiroya Umeda, Masami Ouchi, Satoshi Kikuta +11
We present the luminosity functions (LFs) and angular correlation functions (ACFs) derived from 18,960 Ly emitters (LAEs) at over a wide survey area of $\lesssim24 {…
Strong He I Emission Lines in High N/O Galaxies at Identified in JWST Spectra: High He/H Abundance Ratios or High Electron Densities?
Hiroto Yanagisawa, Masami Ouchi, Kuria Watanabe +14
We present HeI/H-flux and He/H-abundance ratios in three JWST galaxies with significant constraints on N/O-abundance ratios, GS-NDG-9422, RXCJ2248-ID, and GLASS150008 at $z\sim…
Balmer Decrement Anomalies in Galaxies at z ~ 6 Found by JWST Observations: Density-Bounded Nebulae or Excited H I Clouds?
Hiroto Yanagisawa, Masami Ouchi, Kimihiko Nakajima +11
We investigate the physical origins of the Balmer decrement anomalies in GS-NDG-9422 (Cameron et al. 2023) and RXCJ2248-ID (Topping et al. 2024) galaxies at whose $\mathr…
Probing Chemical Enrichment in Extremely Metal-Poor Galaxies
Keita Fukushima, Kentaro Nagamine, Akinori Matsumoto +4
The chemical composition of galaxies offers vital insights into their formation and evolution. In particular, the relationship between helium abundance (He/H) and metallicity serve…
SILVERRUSH. XIII. A Catalog of 20,567 Ly Emitters at Identified in the Full-depth Data of the Subaru/HSC-SSP and CHORUS Surveys
Satoshi Kikuta, Masami Ouchi, Takatoshi Shibuya +13
We present 20,567 Ly emitters (LAEs) at that are photometrically identified by the SILVERRUSH program in a large survey area up to 25 deg with deep images of fiv…
EMPRESS. XIV. Strong High Ionization Lines of Young Galaxies at : Ionizing Spectra Consistent with the Intermediate Mass Black Holes with
Shun Hatano, Masami Ouchi, Hiroya Umeda +16
We present ionizing spectra estimated at 13.6--100 eV for ten dwarf galaxies with strong high ionization lines of He {\sc {ii}}4686 and [Ne {\sc{v}}]3426 ([Ne {\sc{iv}}]24…
EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?
Yuki Isobe, Masami Ouchi, Kimihiko Nakajima +49
We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities () and low stellar masses (). Tak…