A5058402043- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Galaxies: Formation, Evolution, Phenomena
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Dark Matter and Cosmic Phenomena
- Quantum, superfluid, helium dynamics
- Physics of Superconductivity and Magnetism
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Astro and Planetary Science
- Ionosphere and magnetosphere dynamics
- Advanced Condensed Matter Physics
- Radio Astronomy Observations and Technology
- Advanced Thermodynamic Systems and Engines
- Solar and Space Plasma Dynamics
- Neutrino Physics Research
- Atmospheric and Environmental Gas Dynamics
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
Nagoya University
2012-2024
Osaka Prefecture University
2018
Osaka University
2013
The University of Tokyo
1997-2009
National Astronomical Observatory of Japan
2004-2007
Astronomical Observatory
2001
A new survey of the LMC has been completed in 2.6 mm carbon monoxide emission with NANTEN. This revealed 107 giant molecular clouds, first complete sample clouds a single galaxy at linear resolution ∼ 40 pc. The cloud mass ranges from 6 × 104 to 2 106 M⊙, and total estimated be 4–7 M⊙ for column density ≳ 1.0 1021 cm-2, corresponding 5–10% atomic mass. exhibit good spatial correlation youngest stellar clusters whose ages are ≲ 10 Myr, demonstrating that cluster formation is on-going these...
We present new large field observations of molecular clouds with NANTEN2 toward the super star cluster NGC 3603 in transitions 12CO(J = 2–1, J 1–0) and 13CO(J 1–0). suggest that two at 13 km s−1 28 are associated as evidenced by higher temperatures H ii region, well morphological correspondence. The mass is too small to gravitationally bind them, given their relative motion ∼20 s−1. collided each other 1 Myr ago trigger formation cluster. This scenario able explain origin highest stellar...
Hi-GAL is a large-scale survey of the Galactic plane, performed with Herschel in five infrared continuum bands between 70 and 500 $\mu$m. We present band-merged catalogue spatially matched sources their properties derived from fits to spectral energy distributions (SEDs) heliocentric distances, based on photometric catalogs presented Molinari et al. (2016a), covering portion plane $-71.0^{\circ}< \ell < 67.0^{\circ}$. The contains 100922 regular SED, 24584 which show $\mu$m counterpart are...
RX J1713.7$-$3946 is the most remarkable TeV $\gamma$-ray SNR which emits $\gamma$-rays in highest energy range. We made a new combined analysis of CO and \ion{H}{1} derived total protons interstellar medium (ISM). have found that inclusion gas provides significantly better spatial match between ISM than H$_2$ alone. In particular, southeastern rim shell has counterpart only \ion{H}{1}. The finding shows proton distribution consistent with hadronic scenario comic ray (CR) react to produce...
We present the first Herschel PACS and SPIRE photometric observations in a portion of outer Galaxy ($216.5^{\circ} \lesssim \ell 225.5^{\circ}$ $-2^{\circ} b 0^{\circ}$) as part Hi-GAL survey. The maps between 70 500 $\mu$m, derived column density temperature maps, compact source catalog are presented. NANTEN CO(1-0) line used to derive cloud kinematics distances, so that we can estimate distance-dependent physical parameters sources (cores clumps) having reliable spectral energy...
Dark gas in the interstellar medium (ISM) is believed to not be detectable either CO or Hi radio emission, but it detected by other means including gamma-rays, dust emission and extinction traced outside Galactic plane at |b|>5 degree. In these analyses, 21-cm HI usually assumed completely optically thin. We have reanalyzed from whole sky |b|>15 degree considering temperature stratification ISM inferred Planck/IRAS analysis of properties. The results indicate that saturated with an optical...
RX J1713.7−3946 is one of the TeV γ-ray supernova remnants (SNRs) emitting synchrotron X-rays. The SNR associated with molecular gas located at ∼1 kpc. We made new observations toward dense cloud cores, peaks A, C, and D, in 12CO(J = 2–1) 13CO(J transitions an angular resolution 90''. most intense core 13CO, peak was also mapped 4–3) transition 38''. Peak C shows strong signs active star formation including bipolar outflow a far-infrared protostellar source, has steep gradient r−2.2±0.4...
RX J1713.7-3946 is the most remarkable very-high-energy \gamma-ray supernova remnant which emits synchrotron X-rays without thermal features. We made a comparative study of CO, HI and in order to better understand relationship between X-rays, molecular atomic gas. The results indicate that are enhanced around CO clumps on pc scale but decreased inside 0.1 scale. Magnetohydrodynamic numerical simulations shock interaction with gas waves excite turbulence amplifies magnetic field (Inoue et al....
We present an analysis of the interstellar medium (ISM) toward γ-ray supernova remnant (SNR) W44. used NANTEN2 12CO(J = 2–1) and 1–0) data Arecibo H i in order to identify molecular atomic gas SNR. confirmed that is located SNR shell with a primary peak eastern edge shell. newly identified high-excitation along addition broad previously observed inside shell; line intensity ratio between transitions these regions greater than ∼1.0, suggesting kinetic temperature 30 K or higher, which most...
We have carried out a spectral analysis of the Suzaku X-ray data in 0.4–12 keV range toward shell-type very high-energy γ-ray supernova remnant (SNR) RX J1713.7−3946. The aims this are to estimate detailed X-rays properties at high angular resolution up 2 arcmin and compare them with interstellar gas. spectrum is non-thermal used calculate absorbing column density, photon index, absorption-corrected flux. index varies significantly from 2.1 2.9. It shown that intensity well correlated...
We present an analysis of the and CO gas in conjunction with Planck/IRAS submillimeter/far-infrared dust properties toward most outstanding high latitude clouds MBM 53, 54, 55 HLCG 92 − 35 at b = −30° to 45°. The emission, opacity 353 GHz (τ353), temperature (Td) show generally good spatial correspondence. On other hand, correspondence between emission is less clear than CO. integrated intensity τ353 a large scatter correlation coefficient ∼0.6 for Td range from 16 K 22 K. find, however,...
SPLASH (the Southern Parkes Large-Area Survey in Hydroxyl) is a sensitive, unbiased and fully-sampled survey of the Galactic Plane Centre all four ground-state transitions hydroxyl (OH) radical. The provides deep census 1612-, 1665-, 1667- 1720-MHz OH absorption emission from ISM, also an search for maser sources these transitions. We present here first results pilot region, which covers longitudes 334 to 344 degrees latitudes -2 +2 degrees. Diffuse widely detected transitions, with optical...
We present a new analysis of the interstellar protons toward TeV $\gamma$-ray SNR RX J0852.0$-$4622 (G266.2$-$1.2, Vela Jr.). used NANTEN2 $^{12}$CO($J$ = 1-0) and ATCA & Parkes HI datasets in order to derive molecular atomic gas associated with shell SNR. find that over velocity range from $V_\mathrm{LSR}$ $-4$ km s$^{-1}$ 50 or 60 is entire SNR, while limited portion The large dispersion ascribed expanding motion few shells overlapping but not due Galactic rotation. total masses gases are...
Abstract Comparison analyses between the gas emission data ( <?CDATA ${\rm{H}}\,{\rm{I}}\,21\,\mathrm{cm}$?> line and $\mathrm{CO}\,2.6\,\mathrm{mm}$?> line) Planck / IRAS dust (optical depth at $353\,\mathrm{GHz}\,{\tau }_{353}$?> temperature ${T}_{{\rm{d}}}$?> ) allow us to estimate amount distribution of hydrogen more accurately, our previous studies revealed existence a large optically thick ${\rm{H}}\,{\rm{I}}$?> in solar neighborhood. Referring this, we discuss neutral around Perseus...
Abstract A supersonic cloud–cloud collision produces a shock-compressed layer which leads to formation of high-mass stars via gravitational instability. We carried out detailed analysis the by using numerical simulations magneto-hydrodynamics deal with colliding molecular flows at relative velocity 20 km s−1 (Inoue & Fukui 2013, ApJ, 774, L31). Maximum density in increases from 1000 cm−3 more than 105 within 0.3 Myr compression, and turbulence magnetic field are amplified factor ∼5,...
To reveal the origin of mini-starbursts in Milky Way, we carried out large-scale CO observations toward RCW 106 giant molecular cloud (GMC) complex using NANTEN2 4-m radio telescope operated by Nagoya University. We also analyzed Mopra Southern Galactic plane survey and Herschel infrared continuum archival data. The GMC contains radial velocity components $-68$ km s$^{-1}$ $-50$ reported Nguyen et al. (2015). Focusing on East West region with massive star formation having bright dust...
Abstract To reveal the origin of mini-starbursts in Milky Way, we carried out large-scale CO observations toward RCW 106 giant molecular cloud (GMC) complex using NANTEN2 4 m radio telescope operated by Nagoya University. We also analyzed Mopra Southern Galactic Plane survey and Herschel infrared continuum archival data. The GMC contains radial velocity components −68 km s −1 −50 reported H. Nguyen et al. (2015). Focusing on East West region with massive star formation having bright dust...
We present a detailed investigation of the $\gamma$-ray emission in vicinity supernova remnant (SNR) W28 (G6.4$-$0.1) observed by Large Area Telescope (LAT) onboard Fermi Gamma-ray Space Telescope. detected significant spatially coincident with TeV sources HESS J1800$-$240A, B, and C, located outside radio boundary SNR. Their spectra 2-100 GeV band are consistent extrapolation power-law sources. also identified new source emission, dubbed Source W, which lies coincides from western part W28....
ABSTRACT We derived the dust-to-H i ratio of intermediate-velocity clouds (IVCs), high-velocity (HVCs), and local H gas, by carrying out a multiple-regression analysis 21 cm emission combined with sub-mm dust optical depth. The method covers over 80 per cent sky contiguously at resolution 47 arcmin is distinguished from absorption-line measurements toward bright galaxies stars covering tiny fraction sky. Major results include that IVCs in range 0.1–1.5 mode 0.6 (relative to...
New 12CO J=4-3 and 13CO J=3-2 observations of the N159 region in Large Magellanic Cloud have been made. The distribution is separated into three clumps. These new measurements toward clumps are used coupled calculations molecular rotational excitation line radiation transfer, along with other transitions as well isotope 13CO. temperatures densities determined to be ~70-80K ~3x10^3 cm-3 N159W N159E ~30K ~1.6x10^3 N159S. results compared star formation activity. clump associated embedded...
Dense, star-forming gas is believed to form at the stagnation points of large-scale interstellar medium flows, but observational examples this process in action are rare. We here present a giant molecular cloud (GMC) sandwiched between two colliding Milky Way supershells, which we argue shows strong evidence having formed from material accumulated collision zone. Combining 12CO, 13CO, and C18O(J = 1–0) data with new high-resolution, three-dimensional hydrodynamical simulations discuss origin...
Abstract We analyzed the TeV gamma-ray image of a supernova remnant RX J1713.7−3946 (RX J1713) through comparison with interstellar medium (ISM) and nonthermal X-rays. The data sets at two energy bands >2 >250–300 GeV were obtained H.E.S.S. utilized in analysis. employed new methodology, which assumes that counts can be expressed as linear combination terms: one is proportional to ISM column density other X-ray count. then assume these represent hadronic leptonic components,...
We present a study of the structure Galactic interstellar medium (ISM) through Δ-variance technique, related to power spectrum and fractal properties infrared/submillimeter maps. Through this method, it is possible provide quantitative parameters, which are useful for characterizing different morphological physical conditions, better constraining theoretical models. In respect, Herschel Infrared Plane Survey, carried out at five photometric bands from 70 500 μm, constitutes unique database...
Abstract We carried out synthetic observations of interstellar atomic hydrogen at 21 cm wavelength by utilizing the magnetohydrodynamic numerical simulations inhomogeneous turbulent medium. The cold neutral medium (CNM) shows a significantly clumpy distribution with small volume filling factor 3.5%, whereas warm (WNM) has distinctly different and smooth large 96.5%. In projection on sky, CNM exhibits highly filamentary subparsec width, WNM smooth, extended distribution. H i optical depth, is...
Understanding the mechanism of O star formation is one most important issues in current astrophysics. It also an issue keen interest how stars affect their surroundings and trigger secondary formation. An H\,\emissiontype{II} region RCW79 typical Spitzer bubbles alongside RCW120. New observations CO $J=$ 1--0 emission with Mopra NANTEN2 revealed that molecular clouds are associated four velocity components over a range 20 km s$^{-1}$. We hypothesize two collided each other collision...