A5003889965- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Spectroscopy and Laser Applications
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Atmospheric Ozone and Climate
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Advanced Thermodynamic Systems and Engines
- Spacecraft and Cryogenic Technologies
- Microwave Engineering and Waveguides
- Calibration and Measurement Techniques
- Particle Accelerators and Free-Electron Lasers
- Scientific Research and Discoveries
- Laser Design and Applications
- Precipitation Measurement and Analysis
- Antenna Design and Optimization
- Advanced Combustion Engine Technologies
National Astronomical Observatory of Japan
2016-2025
The Graduate University for Advanced Studies, SOKENDAI
2014-2025
The University of Tokyo
1987-2024
Nagoya University
1987-2024
National Institutes of Natural Sciences
2016-2024
Misato Observatory
2002-2017
Atacama Large Millimeter Submillimeter Array
2012-2017
Nippon Soken (Japan)
2016
Netherlands Institute for Radio Astronomy
2013
Okayama Prefecture
2013
Observations of stellar kinematics, gasdynamics, and masers around galactic nuclei have now firmly established that many galaxies host central supermassive black holes (SMBHs) with masses in the range ~106-109 M☉. However, how these SMBHs formed is not well understood. One reason for this situation lack observations intermediate-mass BHs (IMBHs), which could bridge gap between mass SMBHs. Recently, missing link (i.e., an IMBH) has been found made by ASCA Chandra region starburst galaxy M82....
We present the results of an imaging survey protoplanetary disks around single T Tauri stars in Taurus. Thermal emission at 2 mm from dust has been imaged with a maximum spatial resolution 1'' by using Nobeyama Millimeter Array. Disk images have successfully obtained under almost uniform conditions for 13 stars, two which are thought to be embedded. derived disk properties outer radius, surface density distribution, mass, temperature and opacity coefficient, analyzing both our spectral...
We report the source size distribution, as measured by ALMA millimetric continuum imaging, of a sample 13 AzTEC-selected submillimeter galaxies (SMGs) at –6. Their infrared luminosities and star formation rates (SFRs) are 2– ∼200–600 yr−1, respectively. The sizes these SMGs range from 010 to 038, with median 020 (FWHM), corresponding circularized effective radius () kpc, comparable typical stellar component in compact quiescent (cQGs)— kpc. surface SFR density our is yr−1 kpc−2, that seen...
We have used the Submillimeter Array to image a flux-limited sample of seven submillimeter galaxies, selected by AzTEC camera on JCMT at 1.1 mm, in COSMOS field 890 μ m with ~2'' resolution. All sources—two radio-bright and five radio-dim—are detected as single point sources high significance (>6 σ), positions accurate ~0.2'' that enable counterpart identification other wavelengths observed similarly angular IRAC counterparts, but only two secure counterparts deep HST ACS imaging. As...
We have mapped the northern area (30' times 20') of a local group spiral galaxy M33 in 12CO(J=1-0) line with 45-m telescope at Nobeyama Radio Observatory. Along Halpha and Spitzer 24-micron data, we investigated relationship between surface density molecular gas mass that star formation rate (SFR) an external (Kennicutt-Schmidt law) highest spatial resolution (~80pc) to date, which is comparable scales giant clouds (GMCs). At positions where CO significantly detected, SFR exhibits wide range...
We report the results of 15 × 3' mapping at 1.1 mm with Atacama Large Millimeter/submillimeter Array toward central region z = 3.09 SSA22 protocluster. By combining our source catalog archival spectroscopic redshifts, we find that eight submillimeter galaxies (SMGs) flux densities, S1.1 0.7–6.4 mJy (LIR ∼ 1012.1–1013.1 L⊙) are 3.08–3.10. Not only these SMGs members protocluster, but they in fact reside within node junction 50 Mpc scale filamentary three-dimensional structure traced by Lyα...
We present < 1 kpc resolution CO imaging study of 37 optically-selected local merger remnants using new and archival interferometric maps obtained with ALMA, CARMA, SMA PdBI. supplement a sub-sample single-dish measurements at the NRO 45 m telescope for estimating molecular gas mass (10^7 - 10^11 M_sun), evaluating missing flux measurements. Among sources robust detections, we find that 80 % (24/30) sample show kinematical signatures rotating disks (including nuclear rings) in their velocity...
ABSTRACT We report ∼3 au resolution imaging observations of the protoplanetary disk around TW Hya at 145 and 233 GHz with Atacama Large Millimeter/submillimeter Array. Our revealed two deep gaps (∼25%–50%) 22 37 shallower (a few percent) 6, 28, 44 au, as recently reported by Andrews et al. The central hole a radius was also marginally resolved. most remarkable finding is that spectral index between bands 4 6 peaks gap. derived power-law dust opacity ∼1.7 gap decreases toward center to ∼0....
ASTE (Atacama Submillimeter Telescope Experiment) is a project to install and operate 10-m submillimeter telescope in the high altitude site (4,800 m) Atacama desert, northern Chile. The aimed explore southern sky with waves as well develop evaluate various instruments observing techniques. was shipped re-assembled Chilean early 2002, including establishment of on infrastructure. Following evaluation receivers, scientific observations such supernova remnants, galaxies, star forming regions...
We present results from observations of the most famous starburst galaxy M82 with High-Resolution Camera onboard Chandra X-Ray Observatory. found nine sources in central 1' x region, but no source was detected at galactic center. Comparing on 1999 October 28 and 2000 January 20, we four showed significant time variability. In particular, CXOM82J095550.2+694047, which is 9" away center, extremely large conclude that this origin hard X-ray variability ASCA. Assuming a spectral shape obtained...
We give a detailed presentation of all the data from multiepoch 22 GHz H2O maser survey mainly toward low-mass young stellar objects (YSOs) using Nobeyama 45 m telescope and Very Large Array (VLA). Our major results are already published (our Paper I). The is first complete known Class 0 sources in northern sky (δ > -35°) one most sensitive surveys ever performed. was conducted 1996 May through 1999 March over 32 periods. A total 606 observations were carried out 173 YSOs, including 36...
We present a 0.72 deg2 contiguous 1.1-mm survey in the central area of Cosmological Evolution Survey field carried out to 1σ≈ 1.26 mJy beam−1 depth with AzTEC camera mounted on 10-m Atacama Submillimeter Telescope Experiment. have uncovered 189 candidate sources at signal-to-noise ratio (S/N) ≥ 3.5, which 129, S/N 4, can be considered little chance being spurious (≲2 per cent). number counts derived this survey, show significant excess when compared from ∼0.5 sampled similar depths...
We report the results of counterpart identification and a detailed analysis physical properties 48 sources discovered in our deep 1.1mm wavelength imaging survey GOODS-South field using AzTEC instrument on Atacama Submillimeter Telescope Experiment (ASTE). One or more robust tentative candidate is found for 27 14 sources, respectively, by employing radio continuum, Spitzer MIPS & IRAC, LABOCA 870 micron data. Five (10%) have two counterparts each, supporting idea that these galaxies are...
The Serpens South embedded cluster, which is located in the constricted part of a long, filamentary, infrared dark cloud, believed to be very early stage cluster formation. We present results near-infrared (JHKs) polarization observations filamentary cloud. Our measurements point sources indicate well-ordered global magnetic field that perpendicular main filament, implying likely have controlled formation filament. On other hand, sub-filaments, converge on central tend run along field....
We present the first results from a confusion-limited map of Great Observatories Origins Deep Survey-South (GOODS-S) taken with AzTEC camera on Atacama Submillimeter Telescope Experiment. imaged field to 1σ depth 0.48–0.73 mJy beam−1, making this one deepest blank-field surveys at mm-wavelengths ever achieved. Although by traditional standards our GOODS-S is extremely confused due sea faint underlying sources, we demonstrate through simulations that source identification and number counts...
We present a Giant Molecular Cloud (GMC) catalog toward M33, containing 71 GMCs in total, based on wide field and high sensitivity CO(J=3-2) observations with spatial resolution of 100 pc using the ASTE 10 m telescope. Employing archival optical data, we identify 75 young stellar groups (YSGs) from excess surface density, estimate their ages by comparing evolution models. A comparison among GMCs, YSGs, HII regions enable us to classify into four categories: Type showing no sign massive star...
We report the first detection of a gap and ring in 336 GHz dust continuum emission from protoplanetary disk around TW Hya, using Atacama Large Millimeter/Submillimeter Array (ALMA). The are located at 25 41 au central star, respectively, associated with CO snow line ~30 au. has radial width less than 15 mass deficit more 23%, taking into account that observations limited to an angular resolution ~15 In addition, 13CO C18O J = 3 - 2 lines show decrement throughout disk, down ~10 au,...
Aims. We derive physical properties such as the optical depths and column densities of 13CO C18O to investigate relationship between far ultraviolet (FUV) radiation abundance ratios C18O.
Abstract In the past decade, ALMA observations of protoplanetary disks revealed various substructures including gaps and rings. Their origin may be probed through statistical studies their physical properties. We present analyses archival Band 6 continuum data 43 (39 Class II four Herbig Ae) in Taurus–Auriga region. employ a novel 2D super-resolution imaging technique based on sparse modeling to obtain images with high fidelity spatial resolution. As result, we have obtained resolutions...
We present moderate- (1'') and high-resolution (02) observations of the CO (2–1) emission at 43 GHz radio continuum 1.47 from z = 4.7 QSO BRI 1202-0725 4.4 1335-0417 using Very Large Array. The moderate-resolution show that in both cases is spatially resolved into two components separated by 1'' for 4'' 1202-0725. each component has substructure on scales ∼02–05, with intrinsic brightness temperatures ≥20 K. ladder up to (7–6) suggests a high kinetic temperature gas (Tkin ≃ 70 K) column...
We present results of a 1.1-mm deep survey the AKARI Deep Field South (ADF-S) with AzTEC mounted on Atacama Submillimetre Telescope Experiment (ASTE). obtained map 0.25-deg2 area an rms noise level 0.32–0.71 mJy. This is one deepest and widest maps thus far at millimetre submillimetre wavelengths. uncovered 198 sources significance 3.5σ–15.6σ, providing largest catalogue in contiguous region. Most are not detected far-infrared bands satellite, suggesting that they mostly z≥ 1.5 given...