Publications (58)
FINER: Far-Infrared Nebular Emission Receiver for the Large Millimeter Telescope
Yoichi Tamura, Takeshi Sakai, Ryohei Kawabe +34
Unveiling the emergence and prevalence of massive/bright galaxies during the epoch of reionization and beyond, within the first 600 million years of the Universe, stands as a pivot…
Balmer Break Galaxy Candidates at : a Potential View on the Star-Formation Activity at
Ken Mawatari, Akio K. Inoue, Takuya Hashimoto +15
We search for galaxies with a strong Balmer break (Balmer Break Galaxies; BBGs) at over a 0.41 deg effective area in the COSMOS field. Based on rich imaging data, in…
EMPRESS. VIII. A New Determination of Primordial He Abundance with Extremely Metal-Poor Galaxies: A Suggestion of the Lepton Asymmetry and Implications for the Hubble Tension
Akinori Matsumoto, Masami Ouchi, Kimihiko Nakajima +42
The primordial He abundance is a powerful probe of cosmology. Currently, is best determined by observations of metal-poor galaxies, while there are on…
Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
Hiroaki Aihara, Yusra AlSayyad, Makoto Ando +64
The paper presents the third data release of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), a wide-field multi-band imaging survey with the Subaru 8.2m telescope. HSC-SSP ha…
Detections of [OIII] 88 m in Two Quasars in the Reionization Epoch
Takuya Hashimoto, Akio K. Inoue, Yoichi Tamura +3
With the Atacama Large Millimeter/sub-millimeter Array (ALMA), we report detections of the far-infrared (FIR) [OIII] 88 m line and the underlying dust continuum in the two quas…
Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era
Yoichi Tamura, Ken Mawatari, Takuya Hashimoto +19
We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection of the [O III] 88 m line and rest-frame 90 m dust continuum emission in a Y-dropout Lyman break…
RIOJA. A Clumpy Galaxy Assembly at Redshift 6.81 Revealed by JWST
Ken Mawatari, Luca Costantin, Mitsutaka Usui +21
Spatially resolved multi-wavelength analysis is essential to study galaxy formation and evolution. A UV-bright galaxy COS-2987030247 at is one of the Rosetta Stones in t…
The role of small-scale environments in the quenching of massive galaxies at
Takumi Kakimoto, Masayuki Tanaka, Makoto Ando +10
Massive quiescent galaxies (QGs) at high redshifts are likely progenitors of massive elliptical galaxies in the local Universe. Recent observations, such as the discovery of QGs in…
A Search for H-Dropout Lyman Break Galaxies at z~12-16
Yuichi Harikane, Akio K. Inoue, Ken Mawatari +11
We present two bright galaxy candidates at z~12-13 identified in our H-dropout Lyman break selection with 2.3 deg2 near-infrared deep imaging data. These galaxy candidates, selecte…
Deep Submillimeter and Radio Observations in the SSA22 Field. III. Multiwavelength Identifications and Properties of the 850 m-selected Submillimeter Galaxies
Xin Zeng, Yiping Ao, Zongfei Lyu +4
We present a multiwavelength analysis of 850 m-selected SMGs (deblended S 1mJy) in the SSA22 field, where our deepest JCMT/SCUBA-2 observations reach a sensi…
The first direct imaging of the silhouette of a damped Lyman system along the line-of-sight to a background galaxy
Fuga Komori, Akio K. Inoue, Ken Mawatari +7
The H~{\sc i} gas distribution in damped Lyman absorbers (DLAs) has remained elusive due to the point-source nature of background quasar emission. Observing DLAs against spati…
The onset of star formation 250 million years after the Big Bang
Takuya Hashimoto, Nicolas Laporte, Ken Mawatari +21
A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang. Th…
Point Cloud Novelty Detection Based on Latent Representations of a General Feature Extractor
Shizuka Akahori, Satoshi Iizuka, Ken Mawatari +1
We propose an effective unsupervised 3D point cloud novelty detection approach, leveraging a general point cloud feature extractor and a one-class classifier. The general feature e…
Cosmological-Scale Lyman-alpha Forest Absorption Around Galaxies and AGN Probed with the HETDEX and SDSS Spectroscopic Data
Dongsheng Sun, Ken Mawatari, Masami Ouchi +12
We present cosmological-scale 3-dimensional (3D) neutral hydrogen ({\sc Hi}) tomographic maps at over a total of 837 deg in two blank fields that are developed with Ly$…
ALMA uncovers the [CII] emission and warm dust continuum in a z = 8.31 Lyman break galaxy
Tom J. L. C. Bakx, Yoichi Tamura, Takuya Hashimoto +15
We report on the detection of the [CII] 157.7 m emission from the Lyman break galaxy (LBG) MACS0416_Y1 at z = 8.3113, by using the Atacama Large Millimeter/submillimeter Array…
A Comprehensive Study on Galaxies at z~9-16 Found in the Early JWST Data: UV Luminosity Functions and Cosmic Star-Formation History at the Pre-Reionization Epoch
Yuichi Harikane, Masami Ouchi, Masamune Oguri +6
We conduct a comprehensive study on dropout galaxy candidates at using the first 90 arcmin JWST/NIRCam images taken by the early release observations (ERO) and earl…
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 warm ultra-luminous infrared galaxy just 600 million years after the Big Bang
T. J. L. C. Bakx, Laura Sommovigo, Yoichi Tamura +24
We present an Atacama Large Millimeter/submillimeter Array (ALMA) Band 9 continuum detection () of MACS0416_Y1 that confirms the suspected warm dust (91 K) of…
CHORUS. I. Cosmic HydrOgen Reionization Unveiled with Subaru: Overview
Akio K. Inoue, Satoshi Yamanaka, Masami Ouchi +28
To determine the dominant sources for cosmic reionization, the evolution history of the global ionizing fraction, and the topology of the ionized regions, we have conducted a deep…
Cosmological 3D HI Gas Map with HETDEX Ly Emitters and eBOSS QSOs at : IGM-Galaxy/QSO Connection and a 40-Mpc Scale Giant HII Bubble Candidate
Shiro Mukae, Masami Ouchi, Gary J. Hill +20
We present cosmological ( Mpc) distributions of neutral hydrogen (HI) in the inter-galactic medium (IGM) traced by Ly Emitters (LAEs) and QSOs at , selected…
CHORUS II. Subaru/HSC Determination of the Ly Luminosity Function at : Constraints on Cosmic Reionization Model Parameter
Ryohei Itoh, Masami Ouchi, Haibin Zhang +16
We present the Ly luminosity function (LF) derived from 34 Ly emitters (LAEs) at on the sky of deg, the largest sample compared to those in the literature…
Characterization of the distribution of the Llyαemitters in the 53W002 field at z = 2.4
Ken Mawatari, Toru Yamada, Yuki Nakamura +2
We present the results of our wide-field narrow band imaging of the field around the radio galaxy 53W002 at z = 2.390 with Subaru/Suprime-Cam. A custom made filter NB413 centered a…
ATT12: The Antarctic 12-m Terahertz Telescope for Studies of Dusty Galaxies. I. Instrument Sensitivity and Science Forecasts
Koki Wakasugi, Takuya Hashimoto, Nario Kuno +13
We present a feasibility study of the Antarctic 12m Terahertz Telescope (ATT12), a next-generation facility to be constructed at New Dome Fuji in Antarctica, designed to open up th…
Detections of [C II] 158 m and [O III] 88 m in a Local Lyman Continuum Emitter, Mrk 54, and its Implications to High-redshift ALMA Studies
Ryota Ura, Takuya Hashimoto, Akio K. Inoue +17
We present integral field, far-infrared (FIR) spectroscopy of Mrk 54, a local Lyman Continuum Emitter (LCE), obtained with FIFI-LS on the Stratospheric Observatory for Infrared Ast…
Testing an indirect method for identifying galaxies with high levels of Lyman continuum leakage
Satoshi Yamanaka, Akio K. Inoue, Toru Yamada +6
Using a sample of galaxies at with detected Lyman Continuum (LyC) leakage in the SSA22 field, we attempt to verify a proposed indirect method for identifying cases wit…
Characterizing CO Emitters in the SSA22-AzTEC26 Field
Shuo Huang, Hideki Umehata, Ryohei Kawabe +5
We report the physical characterization of four CO emitters detected near the bright submillimeter galaxy (SMG) SSA22-AzTEC26. We analyze the data from Atacama Large Millimeter/sub…
Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): The core of the highest redshift galaxy overdensity at confirmed by NIRSpec/JWST
Takuya Hashimoto, Javier Ãlvarez-Márquez, Yoshinobu Fudamoto +20
The protoclusters in the epoch of reionization, traced by galaxies overdensity regions, are ideal laboratories for studying the process of stellar assembly and cosmic reionization.…
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections
Karl Gebhardt, Erin Mentuch Cooper, Robin Ciardullo +60
We describe the survey design, calibration, commissioning, and emission-line detection algorithms for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The goal of HETDEX…
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…
EMPRESS. III. Morphology, Stellar Population, and Dynamics of Extremely Metal Poor Galaxies (EMPGs): Are EMPGs Local Analogs of High- Young Galaxies?
Yuki Isobe, Masami Ouchi, Takashi Kojima +16
We present the morphology and stellar population of 27 extremely metal poor galaxies (EMPGs) at with metallicities of 0.01--0.1 Z. We conduct multi-component sur…
Possible identification of massive and evolved galaxies At z > 5
Ken Mawatari, Toru Yamada, Giovanni Fazio +2
We report on the identification of the old stellar population galaxy candidates at z > 5. We developed a new infrared color selection scheme to isolate galaxies with the strong Bal…
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}…
3D Distribution Map of HI Gas and Galaxies Around an Enormous Ly Nebula and Three QSOs at Revealed by the HI Tomographic Mapping Technique
Shiro Mukae, Masami Ouchi, Zheng Cai +21
We present an IGM HI tomography map in a survey volume of (cMpc) centered at MAMMOTH-1 nebula and three neighbouring…
JWST/NIRSpec spectroscopy of intermediate-mass quiescent galaxies at
Riku A. Sato, Akio K. Inoue, Yuichi Harikane +9
We present the analysis of three intermediate-mass quiescent galaxies (QGs) with stellar masses of at redshifts using NIRSpec low-resolutio…
Early Low-Mass Galaxies and Star-Cluster Candidates at z~6-9 Identified by the Gravitational Lensing Technique and Deep Optical/Near-Infrared Imaging
Shotaro Kikuchihara, Masami Ouchi, Yoshiaki Ono +7
We present very faint dropout galaxies at z~6-9 with a stellar mass M* down to M*~10^6Mo that are found in deep optical/near-infrared (NIR) images of the full data sets of the Hubb…
EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies
Yi Xu, Masami Ouchi, Yuki Isobe +49
We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of and low stellar masses of $10^4-…
FINER: development of the wideband millimeter-wave receiver system and preparations for first light on the Large Millimeter Telescope
Akio Taniguchi, Yoichi Tamura, Takeshi Sakai +38
The recent discovery of an excess of luminous galaxies in the early Universe necessitates sensitive and wideband millimeter spectroscopy to understand their rapid growth. To addres…
The SSA22 HI Tomography Survey (SSA22-HIT). I. Data Set and Compiled Redshift Catalog
Ken Mawatari, Akio K. Inoue, Toru Yamada +16
We conducted a deep spectroscopic survey, named SSA22-HIT, in the SSA22 field with the DEep Imaging MultiObject Spectrograph (DEIMOS) on the Keck telescope, designed to tomographic…
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 observa…
HETDEX Public Source Catalog 1: 220K Sources Including Over 50K Lyman Alpha Emitters from an Untargeted Wide-area Spectroscopic Survey
Erin Mentuch Cooper, Karl Gebhardt, Dustin Davis +43
We present the first publicly released catalog of sources obtained from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). HETDEX is an integral field spectroscopic survey…
FOREVER22: galaxy formation in protocluster regions
Hidenobu Yajima, Makito Abe, Sadegh Khochfar +14
We present results from a new cosmological hydrodynamics simulation campaign of protocluster (PC) regions, FOREVER22: FORmation and EVolution of galaxies in Extremely-overdense Reg…
Compact Ionized Gas Region Surrounded by Porous Neutral Gas in a Dusty Lyman Break Galaxy at Redshift
Masato Hagimoto, Yoichi Tamura, Akio K. Inoue +9
Porous interstellar medium (ISM) structure in galaxies at the epoch of reionization (EoR) gives us a hint to understand what types of galaxies contribute to reionization. Although…
GREX-PLUS Science Book
PLUS Science Team, Akio K. Inoue, Yuichi Harikane +28
GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) is a mission candidate for a JAXA's strategic L-class mission to be launched in the 2030s. Its primary…
First HETDEX Spectroscopic Determinations of Ly and UV Luminosity Functions at : Bridging a Gap Between Faint AGN and Bright Galaxies
Yechi Zhang, Masami Ouchi, Karl Gebhardt +21
We present Ly and ultraviolet-continuum (UV) luminosity functions (LFs) of galaxies and active galactic nuclei (AGN) at determined by the un-targetted optical spect…
Deep Submillimeter and Radio Observations in the SSA22 Field. IV. Spectral Energy Distributions, Star Formation Histories, and the Infrared-Radio Correlation of the 850 m-selected SMGs
Xin Zeng, Yiping Ao, Ken Mawatari +1
We analyze the spectral energy distributions (SEDs), star formation histories (SFHs), and infrared-radio correlation (IRRC) of 221 850 m-selected submillimeter galaxies (SMGs)…
RIOJA. Complex Dusty Starbursts in a Major Merger B14-65666 at z=7.15
Yuma Sugahara, Javier Ãlvarez-Márquez, Takuya Hashimoto +20
We present JWST NIRCam imaging of B14-65666 ("Big Three Dragons"), a bright Lyman-break galaxy system ( mag) at . The high angular resolution of NIRCam r…
CHORUS. III. Photometric and Spectroscopic Properties of Ly Blobs at
Haibin Zhang, Masami Ouchi, Ryohei Itoh +20
We report the Subaru Hyper Suprime-Cam (HSC) discovery of two Ly blobs (LABs), dubbed z70-1 and z49-1 at and respectively, that are Ly emitters with a b…
RIOJA. JWST and ALMA unveil the inhomogeneous and complex ISM structure in a star-forming galaxy at
Mitsutaka Usui, Ken Mawatari, Javier Ãlvarez-Márquez +21
We report the discovery of a complex, density-stratified interstellar medium (ISM) in the star-forming galaxy COS-2987 at , revealed by the unprecedented synergy between…
SILVERRUSH. IX. Lya Intensity Mapping with Star-Forming Galaxies at z=5.7 and 6.6: A Possible Detection of Extended Lya Emission at 100 comoving kpc around and beyond the Virial-Radius Scale of Galaxy Dark Matter Halos
Ryota Kakuma, Masami Ouchi, Yuichi Harikane +11
We present results of the cross-correlation Ly intensity mapping with Subaru/Hyper Suprime-Cam (HSC) ultra-deep narrowband images and Ly emitters (LAEs) at and $6.6…
RIOJA. Young Starburst and Ionized Gas Outflows in a Galaxy Uncovered by JWST NIRCam and NIRSpec Observations
Yi W. Ren, Akio K. Inoue, Javier Ãlvarez-Márquez +21
We present analysis of JWST NIRCam and NIRSpec observations of the galaxy SXDF-NB1006-2 at , as part of the Reionization and the ISM/Stellar Origins with JWST and ALMA (…
A Search for Massive Galaxy Population in a Protocluster of LAEs at near the Radio Galaxy 53W002
Naoki Yonekura, Masaru Kajisawa, Erika Hamaguchi +2
We searched for massive galaxy population in the known large-scale high-density structure of Lyman emitters (LAEs) at near the radio galaxy 53W002 by using $B,~V,~i^\…
"Big Three Dragons": a z = 7.15 Lyman BreakGalaxy Detected in [OIII] 88 m, [CII] 158 m, and Dust Continuum with ALMA
Takuya Hashimoto, Akio K. Inoue, Ken Mawatari +18
We present new ALMA observations and physical properties of a Lyman Break Galaxy at z=7.15. Our target, B14-65666, has a bright ultra-violet (UV) absolute magnitude, $M_{\rm UV}\ap…
Detailed analysis of multi-line molecular distributions in the Seyfert galaxy NGC 1068: Possible effect of the AGN outflow to the starburst ring
Hiroma Okubo, Toshiki Saito, Shuro Takano +5
We apply principal component analysis (PCA) to the integrated intensity maps of 13 molecular lines of the nearby type-2 Seyfert galaxy NGC 1068 obtained by Atacama Large Millimeter…
Early massive galaxy formation in the core of a galaxy protocluster 650 million years after the Big Bang
Yoshinobu Fudamoto, Yurina Nakazato, Daniel Ceverino +24
Rest-frame optical observations with the James Webb Space Telescope (JWST) have uncovered a population of massive galaxies, exceeding solar masses, present less than a bi…
The role of galaxies and AGN in reionising the IGM -- III : IGM-galaxy cross-correlations at z~6 from 8 quasar fields with DEIMOS and MUSE
Romain A. Meyer, Koki Kakiichi, Sarah E. I. Bosman +6
We present improved results of the measurement of the correlation between galaxies and the intergalactic medium (IGM) transmission at the end of reionisation. We have gathered a sa…
ELPIS: Accelerated metal and dust enrichment in a proto-cluster core at
Hideki Umehata, Yoichi Tamura, Yoshinobu Fudamoto +17
We present a study of the metal, dust, and molecular gas content in galaxies within the A2744-z7p9OD proto-cluster at z ~ 7.88. We focus on two galaxy groups, the Quintet and the C…
Imaging of diffuse HI absorption structure in the SSA22 proto-cluster region at z = 3.1
Ken Mawatari, Akio K. Inoue, Toru Yamada +6
Using galaxies as background light sources to map intervening Lya absorption is a novel approach to study the interplay among galaxies, the circum-galactic medium (CGM), and the in…
Detection of an oxygen emission line from a high redshift galaxy in the reionization epoch
Akio K. Inoue, Yoichi Tamura, Hiroshi Matsuo +14
The physical properties and elemental abundances of the interstellar medium in galaxies during cosmic reionization are important for understanding the role of galaxies in this proc…