533 citations · 914 across the 37 of their papers we have counts for
40 papers
Constraining reionization with persistent homology: a novel summary statistic for wide-field Lyman- emitter observations
Michael M. Wyatt, Nikolaos Triantafyllou, Steven R. Furlanetto +4
The spatial clustering of Lyman- emitters (LAEs) is one of the most promising observables for constraining reionization. In this work, we introduce persistent homology, a popula…
DREAMS: Taking the Temperature of a Massive Galaxy at z ~ 11
L. Parente, E. Vanzella, M. Messa +15
We present a detailed photometric and spectroscopic analysis of Janus-11, a galaxy magnified by a factor 1.6 by the galaxy cluster MACS J0416. It was observ…
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…
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…
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…
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…
DREAMS.II. Galaxy Demographics from Direct Te-Based Metallicities at z~2-10: Tracing the Evolution of the Mass-Metallicity and Fundamental Relations
Moka Nishigaki, Kimihiko Nakajima, Masami Ouchi +6
We present the statistics of line ratios and direct Te-based metallicities from JWST medium-resolution spectra of 292 galaxies at z=2-10, combining DREAMS observations with those o…
Little red dot variability over a century reveals black hole envelope via a giant Einstein cross
Zijian Zhang, Mingyu Li, Masamune Oguri +79
"Little red dots" (LRDs) represent a new population of astronomical objects uncovered by JWST whose nature remains debated. Although many LRDs are suspected as active galactic nucl…
A Black-Hole Envelope Interpretation for Cosmological Demographics of Little Red Dots
Hiroya Umeda, Kohei Inayoshi, Yuichi Harikane +1
Little red dots (LRDs) newly discovered with JWST are active galactic nuclei (AGN) that may represent black hole (BH) growth at the earliest cosmic epochs. These sources show puzzl…
Discovery of a Little Red Dot candidate at in COSMOS-Web based on MIRI-NIRCam selection
Takumi S. Tanaka, Hollis B. Akins, Yuichi Harikane +64
JWST has revealed a new high-redshift population called little red dots (LRDs). Since LRDs may be in the early phase of black hole growth, identifying them in the early universe is…
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…
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,…
Census of Ly Emission from Galaxies at : Evolution of the Ly Luminosity Function and a Late Sharp Cosmic Reionization
Yuta Kageura, Masami Ouchi, Minami Nakane +6
We present the statistical properties of Ly emission in 586 galaxies at , observed by multiple JWST/NIRSpec spectroscopy projects, including JADES, GLASS, CEERS, and…
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 {…
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…
The Physical Origin of Extreme Emission Line Galaxies at High redshifts: Strong {\sc [Oiii]} Emission Lines Produced by Obscured AGNs
Chenghao Zhu, Yuichi Harikane, Masami Ouchi +21
We present deep Subaru/FOCAS spectra for two extreme emission line galaxies (EELGs) at with strong {\sc[Oiii]}5007 emission lines, exhibiting equivalent widths (EWs) o…
JWST, ALMA, and Keck Spectroscopic Constraints on the UV Luminosity Functions at z~7-14: Clumpiness and Compactness of the Brightest Galaxies in the Early Universe
Yuichi Harikane, Akio K. Inoue, Richard S. Ellis +33
We present the number densities and physical properties of the bright galaxies spectroscopically confirmed at . Our sample is composed of 60 galaxies at $z_\mathrm{spec}…
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…
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…
Ly Emission at : Clear Ly Equivalent Width Evolution Indicating the Late Cosmic Reionization History
Minami Nakane, Masami Ouchi, Kimihiko Nakajima +6
We present the evolution of Ly emission derived from 53 galaxies at that are identified by multiple JWST/NIRSpec spectroscopy programs of ERS, GO, DDT, and GTO. The…
Stellar- and AGN-Driven Outflows in JWST Galaxies at z=3-9: More Frequent, Wider Opening Angles, and Mostly Bounded
Yi Xu, Masami Ouchi, Kimihiko Nakajima +5
We study outflows in 130 galaxies with -22<MUV<-16 at z=3-9 identified in JWST NIRSpec and NIRCam WFSS data taken by the ERO, CEERS, FRESCO, GLASS, and JADES programs. We identify…
Census for the Rest-frame Optical and UV Morphologies of Galaxies at : First Phase of Inside-Out Galaxy Formation
Yoshiaki Ono, Yuichi Harikane, Masami Ouchi +7
We present the rest-frame optical and UV surface brightness (SB) profiles for galaxies with mag at - ( of which are spectroscopically confir…