Hiroko Shinnaga
A5078372768- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Spectroscopy and Laser Applications
- Superconducting and THz Device Technology
- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Geomagnetism and Paleomagnetism Studies
- High-pressure geophysics and materials
- Geophysics and Gravity Measurements
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Spacecraft Design and Technology
- Advanced Combustion Engine Technologies
Kagoshima University
2015-2024
National Astronomical Observatory of Japan
2013-2019
Kyoto University
2019
Subaru (Japan)
2013-2014
Caltech Submillimeter Observatory
2004-2012
California Institute of Technology
2004-2012
Harvard University
2004-2005
Center for Astrophysics Harvard & Smithsonian
2002-2004
Ibaraki University
1999-2002
Institute of Astronomy and Astrophysics, Academia Sinica
2000-2002
We determine the magnetic field strength in OMC 1 region of Orion A filament via a new implementation Chandrasekhar-Fermi method using observations performed as part James Clerk Maxwell Telescope (JCMT) B-Fields In Star-Forming Region Observations (BISTRO) survey with POL-2 instrument. combine BISTRO data archival SCUBA-2 and HARP to find plane-of-sky $B_{\rm pos}=6.6\pm4.7$ mG, where $\delta B_{\rm pos}=4.7$ mG represents predominantly systematic uncertainty. develop for measuring angular...
We present the first results from B-fields In STar-forming Region Observations (BISTRO) survey, using Sub-millimetre Common-User Bolometer Array 2 (SCUBA-2) camera, with its associated polarimeter (POL-2), on James Clerk Maxwell Telescope (JCMT) in Hawaii. discuss survey's aims and objectives. describe rationale behind questions which survey will aim to answer. The most important of these is role magnetic fields star formation process scale individual filaments cores dense regions. data...
Abstract The Survey of Water and Ammonia in the Galactic Center (SWAG) covers Central Molecular Zone (CMZ) Milky Way at frequencies between 21.2 25.4 GHz obtained Australia Telescope Compact Array ∼0.9 pc spatial ∼2.0 km s −1 spectral resolution. In this paper, we present data on inner ∼250 (1.°4) Sgr C B2. We focus hyperfine structure metastable ammonia inversion lines ( J , K ) = (1, 1)–(6, 6) to derive column density, kinematics, opacity, kinetic gas temperature. CMZ molecular clouds,...
We present the first detection of polarization around Class 0 low-mass protostar L1157-mm at two different wavelengths. show polarimetric maps large scales (10'' resolution 350 μm) from SHARC-II Polarimeter and smaller (12–45 1.3 mm) Combined Array for Research in Millimeter-wave Astronomy (CARMA). The observations are consistent with each other inferred magnetic field lines aligned outflow. CARMA suggest a full hourglass morphology centered about core; this is only second well-defined...
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...
We present the first submm (865mum) imaging spectral line survey at one arcsecond resolution conducted with Submillimeter Array toward Orion-KL. Within 2x2 GHz bandpasses (lower and upper sidebands, 337.2-339.2GHz 347.2-349.2GHz), we find about 145 lines from 13 species, 6 isotopologues, 5 vibrational excited states. Most nitrogen-bearing molecules are strong hot core, whereas oxygen-bearing peak south-west in so-called compact ridge. Imaging of is shown to be an additional tool improve...
We present the results of dust emission polarization measurements Ophiuchus-B (Oph-B) carried out using Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera with its associated polarimeter (POL-2) on James Clerk Maxwell Telescope (JCMT) in Hawaii. This work is part B-fields In Star-forming Region Observations (BISTRO) survey initiated to understand role magnetic fields star formation for nearby star-forming molecular clouds. a first look at geometry and strength Oph-B. The field...
Abstract We present 850 μ m imaging polarimetry data of the ρ Oph-A core taken with Submillimeter Common-User Bolometer Array-2 (SCUBA-2) and its polarimeter (POL-2) as part our ongoing survey project, <?CDATA ${\boldsymbol{B}}$?> -fields In STar forming RegiOns (BISTRO). The polarization vectors are used to identify orientation magnetic field projected on plane sky at a resolution 0.01 pc. 10 subregions distinct fractions angles in 0.2 pc core; some them can be coherent structure Oph...
Abstract Theoretical and numerical works indicate that a strong magnetic field should suppress fragmentation in dense cores. However, this has never been tested observationally relatively large sample of fragmenting massive Here, we use the polarization data obtained Submillimeter Array Legacy Survey Zhang et al. to build 18 cores where both properties are studied uniform way. We measured level, N mm , within view common all regions ∼0.15 pc, with mass sensitivity ∼0.5 M ☉ spatial resolution...
The Serpens South infrared dark cloud consists of several filamentary ridges, some which fragment into dense clumps. On the basis CCS ($J_N=4_3-3_2$), HC$_3$N ($J=5-4$), N$_2$H$^+$ ($J=1-0$), and SiO ($J=2-1, v=0$) observations, we investigated kinematics chemical evolution these ridges. We find that is extremely abundant along main filament in protocluster clump. emphasize first cluster-forming region where extremely-strong emission detected. CCS-to-N$_2$H$^+$ abundance ratio estimated to...
Abstract We observed 13 Planck cold clumps with the James Clerk Maxwell Telescope/SCUBA-2 and Nobeyama 45 m radio telescope. The N 2 H + distribution obtained telescope is quite similar to SCUBA-2 dust distribution. 82 GHz HC 3 N, CCS, 94 CCS emission are often distributed differently respect emission. emission, which known be abundant in starless molecular cloud cores, very clumpy targets. made deep single-pointing observations DNC, HN C, D , cyclic-C toward nine clumps. detection rate of...
Cool, evolved stars have copious, enriched winds. The structure of these winds and the way they are accelerated is not well known. We need to improve our understanding by studying dynamics from pulsating stellar surface about 10 radii, where radiation pressure on dust fully effective. Some red supergiants highly asymmetric nebulae, implicating additional forces. retrieved ALMA Science Verification data providing images sub-mm line continuum emission VY CMa. This enables us locate water...
Abstract We have obtained sensitive dust continuum polarization observations at 850 μ m in the B213 region of Taurus using POL-2 on SCUBA-2 James Clerk Maxwell Telescope as part B -fields STar-forming Region Observations (BISTRO) survey. These allow us to probe magnetic field ( -field) high spatial resolution (∼2000 au or ∼0.01 pc 140 pc) two protostellar cores (K04166 and K04169) one prestellar core (Miz-8b) that lie within filament. Using Davis–Chandrasekhar–Fermi method, we estimate...
We present the first 865 μm continuum image with subarcsecond resolution obtained Submillimeter Array. These data resolve Orion KL region into hot core, nearby radio source I, submillimeter counterpart to infrared n (radio L), and new sources. The emission from I can be modeled as either result of proton-electron free-free that is optically thick ~100 GHz plus dust accounts for majority flux, or H- gives rise a power-law spectrum index ~1.6. latter model would indicate similar physical...
We have used the SHARP polarimeter at Caltech Submillimeter Observatory to map polarization wavelengths of 350 and 450 micron in a ~2 x 3 arcmin region Orion Molecular Cloud. The covers brightest OMC-1 ridge including Kleinmann-Low (KL) nebula submillimeter source Orion-south. ratio 450-to-350 is ~ 1.3 +/- 0.3 outer parts cloud drops by factor 2 towards KL. consistent with measurements other clouds similar confirms previous placing minimum dusty molecular wavelength micron.
We present single-dish 350 μm dust continuum polarimetry as well HCN and HCO+ J = 4 → 3 rotational emission spectra obtained on NGC 1333 IRAS 4. The indicates a uniform field morphology over 20'' radius from the peak flux of 4A, in agreement with models magnetically supported cloud collapse. around 4B appears to be quite distinct, however, indications depolarization observed toward this source. Inverse P Cygni profiles are line providing clear indication infall gas motions. Taken together,...
Using the partially completed Submillimeter Array with five antennas, we have observed CO J = 2-1 and 3-2 emission from envelope surrounding carbon star V Hya. The high angular resolution (2''-4'') maps show that Hya is powering a bipolar molecular jet an extreme velocity of 70-185 km s-1. axis this high-velocity perpendicular to major flattened disklike envelope, which expanding ~16 There third kinematic component, medium-velocity wind deprojected 40-120 s-1 moving along disk plane. Both...
Submillimeter Array observations of Orion-KL at 1'' resolution in the 440mu/690GHz band reveal new insights about continuum and line emission region. The 440mu flux density measurement from source I allows us to differentiate among various proposed physical models: Source can be well modeled by a ``normal'' protostellar SED consisting proton-electron free-free component low frequencies strong dust submillimeter bands. Furthermore, we find that object SMA1 is clearly distinct hot core....
We used the Submillimeter Array to map angular distribution of H30α recombination line (231.9 GHz) in circumstellar region peculiar star MWC 349A. The resolution was 1.2'', but because high signal-to-noise ratio we measured positions all maser components accuracies better than 0.01'', at a velocity 1 km s−1. two strongest (called high-velocity components) velocities near –14 and 32 s−1 are separated by 0.048'' ± 0.001'' (60 AU) along position angle 102° 1°. emission between beyond these were...
Abstract We present the results of a single-pointing survey 207 dense cores embedded in Planck Galactic Cold Clumps distributed five different environments ( λ Orionis, Orion A, B, plane, and high latitudes) to identify on verge star formation for study initial conditions formation. observed these eight molecular lines at 76–94 GHz using Nobeyama 45 m telescope. find that early-type molecules (e.g., CCS) have low detection rates late-type N 2 H + c-C 3 ) deuterated D DNC) rates, suggesting...
We present a study of the natal core harboring low-mass Class 0 protostar GF 9-2 in filamentary dark cloud 9 using Nobeyama 45 m and CSO 10.4 telescopes OVRO millimeter array. is unique sense that it shows H2O masers, clear signpost formation, but does not have high-velocity large-scale outflow. These facts indicate early enough after star formation still retains some information initial conditions for collapse. Our 350 μm dust continuum image identified protostellar envelope with an extent...
Aims: The main goal of this study is to perform a sub-arcsecond resolution analysis the high-mass star formation region G19.61-0.23, both in continuum and molecular line emission. While centimeter images will be discussed detail forthcoming paper, here we focus on (sub)mm emission, devoting special attention hot core. Results: Our observations resolve HMC into three cores whose masses are order 10^1-10^3 Msun. No submm core presents detectable free-free emission regime, but they appear...
ABSTRACT Polarized dust emission is a key tracer in the study of interstellar medium and star formation. The observed polarization, however, product magnetic field structure, grain properties, alignment efficiency, as well their variations line sight, making it difficult to interpret polarization unambiguously. comparison polarimetry at multiple wavelengths possible way mitigating this problem. We use data from HAWC+ /SOFIA SCUBA-2/POL-2 (from BISTRO survey) analyse NGC 2071 molecular cloud...
We used the Submillimeter Array to image SiO maser emission in v = 1, J 5-4 transition associated with peculiar red supergiant VY Canis Majoris. identified seven components and measured their relative positions linear polarization properties. Five of are coincident within about 150 mas (~200 AU at distance 1.5 kpc); most them may originate circumstellar envelope a radius 50 from star along masers lowest rotational transitions. Our measurements show that two be offset inner stellar (at 3 σ...
We have made synthesis imaging of a starless core in the Taurus molecular cloud L1521F, with two key chemical evolutionary tracers, CCS (JN = 32-21), which traces young phase cores, and N2H+ (J 1-0), until late phase, as well mapping observations submillimeter dust continuum. The peak positions, radial distributions, continuum coincide each other. Unlike other shows dip at center, suggesting that abundance molecule decreases center because depletion reactions. channel maps both lines clearly...