7 citations · 32 across the 32 of their papers we have counts for
33 papers
Can Blue UV-Bright Galaxies Drive Reionization at Cosmic Dawn? An Galaxy with at
Yunjing Wu, Sijia Cai, Yongda Zhu +28
We revisit EBG-1, a gravitationally lensed galaxy at , using newly obtained deep (14 hr) JWST/NIRSpec G235M () spectroscopy. EBG-1 is one of the bluest gala…
A sub-100 pc view at z~5 of a Multiply-Imaged Massive Quiescent Galaxy
Richard Pan, Danilo Marchesini, Joseph F. V. Allingham +34
Recent James Webb Space Telescope spectroscopic surveys reveal an abundance of rapidly assembled early galaxies in the first billion years. Cosmological simulations struggle to rep…
Why is GN-z11 Bright, Compact, and Nitrogen Enhanced? Insights from UV Absorption and Emission Diagnostics
Minami Nakane, Masami Ouchi
We investigate the UV spectrum of GN-z11, a luminous, compact galaxy with strong nitrogen lines, at , using deep JWST/NIRSpec high-resolution IFU and medium-resolution MSA…
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…
VENUS: an ultra-faint galaxy hosting the metal-poor type II supernova at Witnessing the initial metal enrichment with extremely frequent core-collapse supernovae?
Yoshihisa Asada, Seiji Fujimoto, Joseph F. V. Allingham +50
We present the first characterization of the host galaxy of a recently discovered type IIP SN at (SN Eos). SN Eos and its host galaxy are gravitationally lensed and multip…
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…
JWST Absorption-Line Analysis of UV-Bright Galaxies at : Early Chemical Enrichment Traced by C, O, Mg, Al, Si, and Fe
Minami Nakane, Masami Ouchi
We investigate UV absorption lines tracing cool gas in eight bright () galaxies at using deep archival JWST/NIRSpec medium-resolution sp…
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 spectroscopically confirmed, strongly lensed, metal-poor Type II supernova at z = 5.13
David A. Coulter, Conor Larison, Justin D. R. Pierel +88
Observing supernovae (SNe) in the early Universe (z > 3) provides a window into how both galaxies and individual stars have evolved over cosmic time, yet a detailed study of high-r…
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…
Spatially Resolved Physical Properties of Young Star Clusters and Star-forming Clumps in the Brightest z>6 Galaxy, the Strongly Lensed Cosmic Spear at z=6.2
Abdurro'uf, Dan Coe, Tom Resseguier +49
We present spatially resolved analysis of stellar populations in the brightest galaxy known to date (AB mag 23), the strongly lensed MACS0308zD1 (dubbed the ``Cosmic Spear…
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…
VENUS: When Red meets Blue -- A multiply imaged Little Red Dot with an apparent blue companion behind the galaxy cluster Abell 383
Miriam Golubchik, Lukas J. Furtak, Joseph F. V. Allingham +50
We report the discovery of a doubly-imaged Little Red Dot (LRD) candidate behind the galaxy cluster Abell 383, which we dub A383-LRD1. Initially classified as a dropout galaxy in H…
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…
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,…
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…
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…