201 citations · 2.1k across the 98 of their papers we have counts for
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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…
A Galaxy with an Extremely Blue UV Slope at Identified by JWST Spectroscopy: Evidence for a Weak Nebular Continuum and Efficient Ionizing Photon Escape?
Hiroto Yanagisawa, Masami Ouchi, Kimihiko Nakajima +8
We investigate UV continuum slopes of 863 galaxies at using archival JWST/NIRSpec PRISM spectra obtained from major JWST GTO, ERS, and GO programs, including JADES, CE…
Impact of Ly radiation force on super-Eddington accretion onto a massive black hole
Takuya Mushano, Takumi Ogawa, Ken Ohsuga +2
The viability of super-Eddington accretion remains a topic of intense debate, crucial for understanding the formation of supermassive black holes in the early universe. However, th…
Constraining Reionization with Lyα Damping-Wing Absorption in Galaxy Spectra: A Machine Learning Model Based on Reionization Simulations
Hyunbae Park, Intae Jung, Hidenobu Yajima +8
Recently, NIRSpec PRISM/CLEAR observations by JWST have begun providing rest-frame UV continuum measurements of galaxies at , revealing signatures of Ly damping-wing…
Detection of the [O I] 63 m emission line from the quasar J2054-0005
Nozomi Ishii, Takuya Hashimoto, Carl Ferkinhoff +23
We report the highest-redshift detection of [O I] 63 m from a luminous quasar, J2054-0005, at based on the Atacama Large Millimeter/sub-millimeter Array Band 9 observat…
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…
Dynamics of a Galaxy at z > 10 Explored by JWST Integral Field Spectroscopy: Hints of Rotating Disk Suggesting Weak Feedback
Yi Xu, Masami Ouchi, Hidenobu Yajima +9
We investigate the dynamics of GN-z11, a luminous galaxy at , carefully analyzing the public deep integral field spectroscopy (IFS) data taken with JWST NIRSpec IFU. While…
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…
Impacts of stellar wind and supernovae on the star cluster formation: origins of extremely high N/O ratios and multiple stellar populations
Hajime Fukushima, Hidenobu Yajima
We study metal enrichment originating from stellar wind and supernovae in low-metallicity clouds by performing three-dimensional radiation hydrodynamics simulations. We find that m…
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…
Violent starbursts and quiescence induced by FUV radiation feedback in metal-poor galaxies at high-redshift
Kazuyuki Sugimura, Massimo Ricotti, Jongwon Park +2
JWST observations of galaxies at suggest that they are more luminous and clumpier than predicted by most models, prompting several proposals on the physics of star for…
Primordial Rotating Disk Composed of 15 Dense Star-Forming Clumps at Cosmic Dawn
S. Fujimoto, M. Ouchi, K. Kohno +43
Early galaxy formation, initiated by the dark matter and gas assembly, evolves through frequent mergers and feedback processes into dynamically hot, chaotic structures. In contrast…
Three-dimensional radiation hydrodynamics simulations of wandering intermediate-mass black holes considering the anisotropic radiation and dust sublimation
Erika Ogata, Ken Ohsuga, Hajime Fukushima +1
By performing three-dimensional radiation hydrodynamics simulations, we study Bondi-Hoyle-Lyttleton accretion onto intermediate-mass black holes (BHs) wandering in the dusty gas. H…