143 citations · 285 across the 37 of their papers we have counts for
39 papers · 1 filter
Diverse Protoclusters at Disclosed by Systematic Spectroscopy
Jun Toshikawa, Kentaro Koretomo, Nobunari Kashikawa +6
We present the results from follow-up spectroscopy of three protocluster candidates at , selected as overdense regions of -dropout galaxies in the wide-field imaging of…
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…
SN Helios: A Multiply Imaged Type II Supernova Opening Time-Delay Cosmography beyond redshift of 3
Seiji Fujimoto, Conor Larison, Justin D. R. Pierel +64
We report the discovery and spectroscopic confirmation of SN Helios, a strongly lensed, multiply imaged Type II supernova (SN) at behind the galaxy cluster RXC J0018.5+162…
H I Absorbers as Beacons of Hidden Structure at : Multi-Component, Metal-Rich Absorption System near a Protocluster
Kentaro Koretomo, Nobunari Kashikawa, Toru Misawa +12
H I gas traces the large-scale structure and provides the primary fuel for star formation. High- protoclusters are ideal laboratories to study how H I gas is accreted and consum…
SERENADE III: Insight into the Origin of the High Dust Temperature and High [O III]/[C II] Ratio at
Ikki Mitsuhashi, Yuichi Harikane, Hiddo S. B. Algera +10
We present an analysis of ALMA high-frequency observations of nine bright Lyman-break galaxies at . Our sample consists of five galaxies at newly obs…
ATLAS. IV. A JWST+MUSE Demographic Study of Ly Profiles in Little Red Dots
Yuta Kageura, Masami Ouchi, Hiroto Yanagisawa +6
We present an initial demographic study of Ly profiles in little red dots (LRDs) at --9 using --4000 spectroscopy. Our sample consists of 8 LRDs observed in the…
ATLAS. III. Dust Around Little Red Dots: Hydrogen Line Ratios beyond Dust-free Non-Case B Models
Tomokazu Kiyota, Masami Ouchi, Hiroto Yanagisawa +7
We investigate broad hydrogen line ratios in little red dots (LRDs) using five high-redshift () sources from JWST/NIRSpec medium/high-resolution spectra in the DAWN JWST Archi…
ATLAS. II. Extremely High Incidence of Balmer Line Absorption with Predominant Blueshifts in LRDs: Statistical Insights through Comparison with Type 1 AGNs
Hiroto Yanagisawa, Masami Ouchi, Tomokazu Kiyota +6
We present the statistical properties of H and H line absorption in little red dots (LRDs) at --7.2 using archival JWST/NIRSpec spectra from the DAWN JWST Archive…
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…
ATLAS. I. A Scaling Relation of LRDs between Broad H and Bolometric Luminosities: Enhanced Broad H Emission Relative to Low- Type 1 AGN
Hiroto Yanagisawa, Masami Ouchi, Tomokazu Kiyota +6
We investigate the demography of little red dots (LRDs) using 37 objects at - with JWST/NIRSpec PRISM and grating spectra compiled from various JWST programs. We focus o…
Assessing the Impact of Source Confusion for GREX-PLUS based on Deep JWST NIRCam Imaging
Yoshiaki Ono, Akio K. Inoue, Yuma Sugahara +9
We investigate the effects of source confusion expected in observations with GREX-PLUS, a JAXA L-class space infrared telescope mission candidate with a wide-field infrared camera…
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…
Chemical Abundance Ratios of Nitrogen Rich Galaxies Identified at : Observational Demographics and Models
Kuria Watanabe, Masami Ouchi, Kimihiko Nakajima +13
We present chemical abundance ratios of 8 nitrogen-rich ([N/O]) galaxies at identified by the first 4 years of the JWST observations, and compare these ratios wi…
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…
VENUS: A Strongly Lensed Clumpy Galaxy at behind the Galaxy Cluster MACS J0257.1-2325
Minami Nakane, Vasily Kokorev, Seiji Fujimoto +75
We present the discovery of a strongly lensed galaxy at , dubbed the ``Misty Moons'', identified in the JWST Treasury Survey, Vast Exploration for Nascent, Unexplored S…
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…
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…
JWST & ALMA Joint Analysis with [OII]3726,3729, [OIII]4363, [OIII]88m, and [OIII]52m: Multi-Zone Evolution of Electron Densities at and Its Impact on Metallicity Measurements
Yuichi Harikane, Ryan L. Sanders, Richard Ellis +8
We present a JWST and ALMA detailed study of the ISM properties of high-redshift galaxies. Our JWST/NIRSpec IFU spectroscopy targeting three galaxies at detects key rest-fr…
Comprehensive JWST+ALMA Study on the Extended Ly Emitters, Himiko and CR7 at : Blue Major Merger Systems in Stark Contrast to Submillimeter Galaxies
Tomokazu Kiyota, Masami Ouchi, Yi Xu +14
We present various properties of two bright extended Ly objects, Himiko and CR7, at thoroughly investigated with JWST/NIRCam photometry, NIRSpec-IFU spectroscopy, and AL…
Fe Abundances of Early Galaxies at Derived with Deep JWST Spectra
Minami Nakane, Masami Ouchi, Kimihiko Nakajima +12
We derive Fe-abundance ratios of 7 galaxies at with whose JWST/NIRSpec spectra achieve very high signal-to-noise ratios, , a…
Morphological Demographics of Galaxies at : Log-Normal Size Distribution and Exponential Profiles Consistent with the Disk Formation Scenario
Yoshiaki Ono, Masami Ouchi, Yuichi Harikane +5
We homogeneously investigate the morphological properties of galaxies at with deep JWST NIRCam images employing our established techniques of GALFIT modeling 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…
A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). X. The Massive and Passive Nature of Radio Galaxies at
Yuta Yamamoto, Tohru Nagao, Takuji Yamashita +8
High- radio galaxies (HzRGs) are considered important objects for understanding the formation and evolution of massive galaxies in the early universe. However, till date, detail…