A5062296890- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Advanced Chemical Physics Studies
- Spectroscopy and Laser Applications
- Mechanics and Biomechanics Studies
- Superconducting and THz Device Technology
- Planetary Science and Exploration
- Pulsars and Gravitational Waves Research
- Laser-induced spectroscopy and plasma
- Remote Sensing and Land Use
- Experimental and Theoretical Physics Studies
- GNSS positioning and interference
- Distributed and Parallel Computing Systems
- Fuel Cells and Related Materials
- Radio Astronomy Observations and Technology
- Atomic and Molecular Physics
- Inorganic Fluorides and Related Compounds
Denso (United States)
2024
Tokyo Denki University
2023
National Astronomical Observatory of Japan
2010-2021
RIKEN
2017-2019
Pioneer (Japan)
2018-2019
Ibaraki University
2014-2016
Tokyo Institute of Technology
2009-2015
Atacama Large Millimeter Submillimeter Array
2012-2014
Soka University of America
2012
Misato Observatory
2009
Aims: The aim of this work is to study the structure protoplanetary disk surrounding Herbig Ae star HD 163296. Methods: We have used high-resolution and high-sensitivity ALMA observations CO(3-2) emission line continuum at 850 microns, as well 3- dimensional radiative transfer code MCFOST model data presented in work. Results: unveils for first time sub-millimeter frequencies vertical details a gaseous Keplerian rotation, showing back- front-side flared disk. Continuum microns reveals...
To date, about two dozen low-mass embedded protostars exhibit rich spectra with lines of complex organic molecule (COM). These seem to possess different enrichment in COMs. However, the statistics COM abundance are limited by scarcity observations. This study introduces Perseus ALMA Chemistry Survey (PEACHES), which aims at unbiasedly characterizing chemistry COMs toward (Class 0/I) molecular cloud. Of 50 surveyed, 58% them have emission from A 56%, 32%, and 40% CH$_3$OH, CH$_3$OCHO,...
The FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) project is one of legacy projects using new multi-beam receiver installed on telescope. This aims to investigate distribution, kinematics, and physical properties both diffuse dense molecular gas in Galaxy at once by observing 12CO, 13CO, C18O J=1-0 lines simultaneously. mapping regions are a part 1st quadrant (10d < l 50d, |b| 1d) 3rd (198d <236d, Galaxy, where spiral arms, bar structure, ring...
Abstract We have resolved for the first time radial and vertical structures of almost edge-on envelope/disc system low-mass Class 0 protostar L1527. For that, we used Atacama Large Millimetre/submillimetre Array (ALMA) observations with a spatial resolution 0.25 × 0.13 arcsec2 0.37 0.23 at 0.8 1.2 mm, respectively. The L1527 dust continuum emission has deconvolved size 78 21 au2, shows flared disc-like structure. A thin infalling-rotating envelope is seen in CCH outward about 150 au, its...
We report molecular line observations of the NGC 1333 IRAS 4C outflow in Perseus Molecular Cloud with Atacama Large Millimeter/Submillimeter Array. The CCH and CS emission reveal an cavity structure clear signatures rotation respect to axis. is detected from about 120 au up 1400 above envelope/disk mid-plane. As distance central source increases, velocity decreases while radius which gives a flat specific angular momentum distribution along outflow. mean 100 km/s. Based on reasonable...
We have detected [C I] 3P1-3P0 emissions in the gaseous debris disks of 49 Ceti and Beta Pictoris with 10 m telescope Atacama Submillimeter Telescope Experiment, which is first detection such emissions. The line profiles are found to resemble those CO(J=3-2) observed same Large Millimeter/submillimeter Array. This result suggests that atomic carbon (C) coexists CO disks, likely formed by photodissociation CO. Assuming an optically thin emission excitation temperature ranging from 30 100 K,...
The Class 0 protostar, L483, has been observed in various molecular lines the 1.2 mm band at a sub-arcsecond resolution with ALMA. An infalling-rotating envelope is traced by CS line, while very compact component broad velocity width for CS, SO, HNCO, NH$_2$CHO, and HCOOCH$_3$ lines. Although this source regarded as warm carbon-chain chemistry (WCCC) candidate 1000 au scale, complex organic molecules characteristic of hot corinos such NH$_2$CHO are detected vicinity protostar. Thus, both...
We present the results of CO ($J=3-2$) and HCO$^+$ ($J=4-3$) mapping observations toward a nearby embedded cluster, Serpens South, using ASTE 10 m telescope. Our map reveals that many outflows are crowded in dense cluster-forming clump can be recognized as with size $\sim$ 0.2 pc mass 80 M$_\odot$. The contains several subfragments sizes 0.05 pc. By comparing 1.1 mm dust continuum image taken by AzTEC on ASTE, we find spatial extents outflow lobes sometimes anti-correlated distribution gas...
We used the Atacama Large (sub-)Millimeter Array (ALMA) and IRAM Plateau de Bure Interferometer (PdBI) to image, with an angular resolution of 0.5$''$ (120 au) 1$''$ (235 au), respectively, emission from 11 different organic molecules in protostellar binary NGC1333 IRAS 4A. clearly disentangled A1 A2, two cores present. For first time, we were able derive column densities fractional abundances simultaneously for objects, allowing us analyse chemical differences between them. Molecular is...
Abstract Characterizing the physical properties of dust grains in a protoplanetary disk is critical to comprehending planet formation process. Our study presents Atacama Large Millimeter/submillimeter Array (ALMA) high-resolution observations young around DG Tau at 1.3 mm continuum. The observations, with spatial resolution ≈0.″04, or ≈5 au, revealed geometrically thin and smooth without substantial substructures, suggesting that retains initial conditions formation. To further analyze...
We present the results of N$_2$H$^+$ ($J=1-0$) observations toward Serpens South, nearest cluster-forming, infrared dark cloud. The physical quantities are derived by fitting hyperfine structure N$_2$H$^+$. Herschel and 1.1-mm continuum maps show that a pc-scale filament fragments into three clumps with radii $0.1-0.2$ pc masses $40-230M_\odot$. find contain smaller-scale ($\sim 0.04$ pc) structures, i.e., dense cores. identify 70 cores applying CLUMPFIND to data cube. In central...
Abstract We observed the Class I protostellar source Elias 29 with Atacama Large Millimeter/submillimeter Array. detected CS, SO, 34 SO 2 , and SiO line emissions in a compact component concentrated near protostar, ridge separated from protostar by 4″ (∼500 au). The former is abundant but deficient CS. abundance ratio SO/CS as high <?CDATA ${3}_{-2}^{+13}\times {10}^{2}$?> at which even higher than that outflow-shocked region of L1157 B1. However, organic molecules (HCOOCH 3 CH OCH CCH, c-C...
We have carried out a survey of the dense clumps associated with 14 embedded clusters in C^18O (J=1-0) line emission Nobeyama 45m telescope order to understand formation and evolution stellar molecular clouds. selected these at distances from 0.3 2.1kpc mapped about 6' X 10' 10'regions (corresponding 3.8pc 2.1kpc) for all 22" resolution Jeans length 2.1kpc). obtained radii 0.40-1.6pc, masses 150-4600M_sun, velocity widths FWHM 1.4-3.3kms^-1. Most are found be approximately virial...
Abstract The origin and evolution of gas in debris disks are still not well understood. Secondary production from cometary material or a primordial have been proposed. So far, observations mostly concentrated on CO, with only few C available. We overview the CO content disk test state-of-the-art models. use new archival Atacama Large Millimeter/submillimeter Array (ALMA) i emission, complemented by ii data Herschel, for sample 14 disks. This expands number ALMA measurements both 10 present...
We have investigated the effect of stellar encounters on formation and disruption Oort cloud using classical impulse approximation. calculate evolution a planetesimal disk into spherical due to perturbation from passing stars for 10 Gyr. obtain empirical fits e-folding time number comets standard exponential Kohlrausch formulae as functions parameters initial semimajor axes planetesimals. The timescales orbital elements are also analytically derived. In some calculations, Galactic tide is...
Chemical diversity of the gas in low-mass protostellar cores is widely recognized. In order to explore its origin, a survey chemical composition toward 36 Class 0/I protostars Perseus molecular cloud complex, which are selected an unbiased way under certain physical conditions, has been conducted with IRAM 30 m and NRO 45 telescope. Multiple lines C2H, c-C3H2 CH3OH have observed characterize averaged over 1000 au scale around protostar. The derived beam-averaged column densities show...
We present the results of sulfur monoxide, SO line emission observations G0.253+0.016 with Atacama Large Millimeter/submillimeter Array (ALMA) at an angular resolution 1.7 arcsec. The dense and massive molecular cloud is highly sub-structured, yet shows no obvious signs cluster formation. found three outstanding features from emission, namely, shell structure radius 1.3 pc, large velocity gradients 20 km/s/pc cloud, cores dispersions (30-40 km/s) around structure. suggest that these...
L1551 is chosen because it relatively isolated in the Taurus molecular cloud shielded from FUV photons, providing an ideal environment for studying target properties. Our observations cover ~40'x40' with resolution ~30", which are maps highest spatial dynamical range to date. We derive X(13CO)/X(C18O) value on sub-parsec scales of ~3-27 a mean 8.0+-2.8. Comparing visual extinction map derived Herschel observations, we found that abundance ratio reaches its maximum at low Av (i.e., ~ 1-4mag),...
We report the H13CO+(1-0) survey observations toward embedded clusters obtained using Nobeyama 45m telescope, which were performed to follow up our previous study in C18O with a dense gas tracer. Our aim is address evolution of cluster-forming clumps. observed same 14 C18O, are located at distances from 0.3-2.1kpc 27" resolution H13CO+. detected 13 clumps H13CO+ line emission and physical parameters radii 0.24-0.75pc, masses 100-1400Msun, velocity widths FWHM 1.5-4.0kms^-1. The mean density...
We present initial results from the CO survey toward high redshift galaxies using Nobeyama 45m telescope. Using new wide bandwidth spectrometer equipped with a two-beam SIS receiver, we have robust detections of three (z=1.6-3.4) submillimeter (SXDF 1100.001, SDP9, and SDP17), one tentative detection (SDSS J160705+533558), non-detection (COSMOS-AzTEC1). The observed during commissioning phase are sources known spectroscopic redshifts previous optical or wide-band submm spectroscopy. derived...
We present the first sub-arcsecond images of 49 Ceti in [C I]3P1-3P0 emission and 614 micron dust continuum observed with ALMA, as well that CO(J=3-2) prepared by using ALMA archival data. The spatial distribution is found to have a broad-ring structure radius about 100 au around central star. A substantial amount gas also associated Ceti. I] map shows two peaks inside ring, its overall extent comparable CO emission. find I]/CO(J=3-2) intensity ratio significantly varies along major axis....
The Black Hole Explorer (BHEX) is a next-generation space very long baseline interferometry (VLBI) mission concept that will extend the ground-based millimeter/submillimeter arrays into space. mission, closely aligned with science priorities of Japanese VLBI community, involves an active engagement this community in development resulting formation Japan Consortium. Here we present current vision for ranging from scientific objectives to instrumentation. Consortium anticipates wide range...
The Black Hole Explorer (BHEX) is a next-generation space very long baseline interferometry (VLBI) mission concept that will extend the ground-based millimeter/submillimeter arrays into space. mission, closely aligned with science priorities of Japanese VLBI community, involves an active engagement this community in development resulting formation Japan Consortium. Here we present current vision for ranging from scientific objectives to instrumentation. Consortium anticipates wide range...
We present the results of SiO (2-1) and SO2 (12-13) line observations Sgr B2(N) made with Atacama Large Millimeter/submillimeter Array (ALMA) at an angular resolution ~2arcsec. Our analysis emission reveals a bipolar molecular outflow in east-west direction whose driving source is located K2. In addition, core shows north-south velocity gradient most probably indicating hot gas rotating around Fractional abundances (X(SO2) X(SiO), respectively) outflowing are derived from comparisons C18O...