Akiyoshi Tsujita
A5006165360- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Precipitation Measurement and Analysis
- Microwave Engineering and Waveguides
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
The University of Tokyo
2022-2024
Abstract We present a statistical study of 180 dust continuum sources identified in 33 massive cluster fields by the Atacama Large Millimeter/submillimeter Array Lensing Cluster Survey (ALCS) over total 133 arcmin 2 area, homogeneously observed at 1.2 mm. ALCS enables us to detect extremely faint millimeter lensing magnification, including near-infrared (NIR) dark objects showing no counterparts existing Hubble Space Telescope and Spitzer images. The belong blind sample ( N = 141) with...
Observations of low order CO transitions represent the most direct way to study galaxies' cold molecular gas, fuel star formation. Here we present first detection CO(2-1) in a galaxy lying on main-sequence star-forming galaxies at z>6. Our target, G09-83808 z=6.03, has short depletion time-scale T_dep~50Myr and relatively gas fraction M_gas/M_star=0.30 that contrasts with those measured for lower redshift galaxies. We conclude this is undergoing starburst episode high formation efficiency...
Unveiling the emergence and prevalence of massive/bright galaxies during epoch reionization beyond, within first 600 million years Universe, stands as a pivotal pursuit in astronomy. Remarkable progress has been made by <i>JWST</i> identifying an immense population bright galaxies, which hints at exceptionally efficient galaxy assembly processes. However, underlying physical mechanisms propelling their rapid growth remain unclear. With this mind, millimeter submillimeter-wave spectroscopic...
We present a statistical study of 180 dust continuum sources identified in 33 massive cluster fields by the ALMA Lensing Cluster Survey (ALCS) over total 133 arcmin$^{2}$ area, homogeneously observed at 1.2 mm. ALCS enables us to detect extremely faint mm lensing magnification, including near-infrared (NIR) dark objects showing no counterparts existing {\it Hubble Space Telescope} and Spitzer} images. The belong blind sample ($N=141$) with S/N $\gtrsim$ 5.0 (a purity $>$ 0.99) or secondary...
We present observations of [NII] 205 $μ$m, [OIII] 88 $μ$m and dust emission in a strongly-lensed, submillimeter galaxy (SMG) at $z=6.0$, G09.83808, with the Atacama Large Millimeter/submillimeter Array (ALMA). Both line emissions are detected $>12σ$ 0.8$"$-resolution maps. Lens modeling indicates that spatial distribution continuum is well characterized by compact disk an effective radius 0.64$\pm$0.02 kpc high infrared surface brightness $Σ_\mathrm{IR}=(1.8\pm0.3)\times10^{12}~L_\odot$...
The ALMA lensing cluster survey (ALCS) is a 96-hr large program dedicated to uncovering and characterizing intrinsically faint continuum sources line emitters with the assistance of gravitational lensing. All 33 fields were selected from HST/Spitzer treasury programs including CLASH, Hubble Frontier Fields, RELICS, which also have Herschel Chandra coverages. total sky area surveyed reaches $\sim$133 arcmin$^2$ down depth $\sim$60 $\mu$Jy beam$^{-1}$ (1$\sigma$) at 1.2 mm, yielding 141 secure...
Unveiling the emergence and prevalence of massive/bright galaxies during epoch reionization beyond, within first 600 million years Universe, stands as a pivotal pursuit in astronomy. Remarkable progress has been made by JWST identifying an immense population bright galaxies, which hints at exceptionally efficient galaxy assembly processes. However, underlying physical mechanisms propelling their rapid growth remain unclear. With this mind, millimeter submillimeter-wave spectroscopic...
We present results from Atacama Large Millimeter/submillimeter Array (ALMA) spectral line-scan observations at 3-mm and 2-mm bands of three near-infrared-dark (NIR-dark) galaxies behind two massive lensing clusters MACS J0417.5-1154 RXC J0032.1+1808. Each these sources is a faint (de-lensed $S_{\text{1.2 mm}}$ $<$ 1 mJy) triply lensed system originally discovered in the ALMA Lensing Cluster Survey. have successfully detected CO [C I] emission lines confirmed that their spectroscopic...
We present the on-sky commissioning and science verification of DESHIMA 2.0: first science-grade integrated superconducting spectrometer (ISS) for ultra-wideband mm-submm spectroscopy. With an instantaneous band coverage 205-392 GHz at a spectral resolution F/dF = 500, 2.0 will be applied to emission line surveys redshift measurement dusty star-forming galaxies, spectroscopic Sunyaev–Zeldovich effect observations galaxy-clusters, other new cases that utilize its ultra-wide bandwidth....
We present a plan for sub/millimeter-wave line intensity mapping (LIM) using an imaging spectrograph based on the Terahertz Integral Field Units with Universal Nanotechnology (TIFUUN) architecture. aim to measure dust-enshrouded cosmic star formation rate density within first 2 billion years by conducting LIM observations of ionized carbon [C II] 158 μm and oxygen [O III] 88 lines, redshifted sub/millimeter wavelengths. The proposed will simultaneously observe two frequency bands: Band-1...
Abstract The tip of the tidal tail, resulting from an encounter between galaxies, features gas concentrations and some star-forming regions, such as dwarf galaxies (TDGs). This region provides a unique laboratory for examining star formation process in dynamical environment distinct that disk galaxies. Using Nobeyama 45 m telescope, we conducted 12 CO(1−0) position-switching observations at tips southern tail Antennae We detected CO emission not only two TDG candidates but also regions with...
Abstract We report the detection of CO(12–11) line emission toward G09-83808 (or H-ATLAS J090045.4+004125), a strongly-lensed submillimeter galaxy at z = 6.02, with Atacama Large Millimeter/submillimeter Array observations. Combining previously detected [O iii] 88 μm, [N ii] 205 and dust continuum 0.6 mm 1.5 mm, we investigate physical properties multi-phase interstellar medium in G09-83808. A source-plane reconstruction reveals that region is compact ($R_\mathrm{{e,...
We report the detection of CO(12-11) line emission toward G09-83808 (or H-ATLAS J090045.4+004125), a strongly-lensed submillimeter galaxy at $z = 6.02$, with Atacama Large Millimeter/submillimeter Array observations. Combining previously detected [O III]$\,88\:\mathrm{μm}$, [N II]$\,205\:\mathrm{μm}$, and dust continuum 0.6$\:$mm 1.5$\:$mm, we investigate physical properties multi-phase interstellar medium in G09-83808. A source-plane reconstruction reveals that region is compact...