A5069010767- Superconducting and THz Device Technology
- Atmospheric Ozone and Climate
- Planetary Science and Exploration
- Astrophysics and Star Formation Studies
- Spectroscopy and Laser Applications
- Astro and Planetary Science
- Ionosphere and magnetosphere dynamics
- Physics of Superconductivity and Magnetism
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Space Exploration and Technology
- Molecular Spectroscopy and Structure
- Precipitation Measurement and Analysis
- Advanced Thermodynamic Systems and Engines
- Spacecraft and Cryogenic Technologies
- Spacecraft Design and Technology
- Soil Moisture and Remote Sensing
- Gyrotron and Vacuum Electronics Research
- Gamma-ray bursts and supernovae
- Microwave Engineering and Waveguides
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
Osaka Prefecture University
2013-2024
Nagoya University
2005-2024
Waseda University
2024
Osaka Metropolitan University
2022-2024
Tokyo Metropolitan University
2023
Yaskawa Electric (Japan)
2016
High Energy Accelerator Research Organization
2015
The University of Tokyo
1999-2004
National Astronomical Observatory of Japan
2003-2004
Misato Observatory
2003
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...
We present fully sampled ∼3' resolution images of 12CO(J = 2–1), 13CO(J and C18O(J 2–1) emission taken with the newly developed 1.85 m millimeter–submillimeter telescope over entire area Orion A B giant molecular clouds. The data were compared J 1–0 12CO, 13CO, C18O Nagoya 4 NANTEN at same angular to derive spatial distributions physical properties gas. explore large velocity gradient formalism determine gas density temperature using line combinations 1–0) assuming a uniform abundance ratio...
A large-scale study of the molecular clouds toward Trifid Nebula, M20, has been made in J = 2–1 and 1–0 transitions 12CO 13CO. M20 is ionized predominantly by an O7.5 star HD164492. The revealed that there are two components at separate velocities peaked center their temperatures—30–50 K as derived a large velocity gradient analysis—are significantly higher than 10 surroundings. We identify parent first generation stars M20. mass each cloud estimated to be ∼103 M☉ separation ∼8 km s−1 over...
Furukawa et al. reported the existence of a large mass molecular gas associated with super star cluster Westerlund 2 and surrounding H ii region RCW49, based on strong morphological correspondence between NANTEN2 12CO(J = 2–1) emission Spitzer IRAC images region. We here present temperature density distributions in at ∼3.5 pc resolution, as derived from velocity gradient analysis 2–1), 1–0), 13CO(J transitions. The kinetic is high ∼60–150 K within projected distance ∼5–10 decreases to low...
Thin superconducting NbTiN and NbN films with a few nm thickness are used in various device applications including hot electron bolometer mixers. Such thin have lower critical temperature (Tc) higher resistivity than corresponding bulk materials. In an effort to improve them, we investigated effect of the AlN buffer layer between film substrate (quartz or soda lime glass). The is deposited by DC magnetron sputtering, process condition optimized so that x-ray diffraction intensity from 002...
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...
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...
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...
Large-scale mapping observations of the 3P1-3P0 fine-structure transition atomic carbon (C i, 492 GHz) and J=3-2 CO (346 toward Orion A molecular cloud have been carried out with Mount Fuji submillimeter-wave telescope. The cover 9 deg2 include Nebula M42 L1641 dark complex. C i emission extends over almost entire region is surprisingly similar to that 13CO (J=1-0). (J=3-2) shows a more featureless extended distribution than i. i/CO integrated intensity ratio spatial gradient running from...
Abstract We have developed a new mm-submm telescope with diameter of 1.85-m installed at the Nobeyama Radio Observatory. The scientific goal is to precisely reveal physical properties molecular clouds in Milky Way Galaxy by obtaining large-scale distribution gas, which can also be compared observations various wavelengths. target frequency $\sim$230 GHz; simultaneous rotational lines $J =$2–1 three carbon monoxide isotopes ($^{12}$CO, $^{13}$CO, C$^{18}$O) are achieved beam size (HPBW)...
The Superconducting Submillimeter-Wave Limb-Emission Sounder 2 (SMILES-2) is a satellite mission that will be proposed to the Japan Aerospace Exploration Agency (JAXA) for launch after 2023. It scan atmospheric limb from lower stratosphere thermosphere retrieving profiles of temperature between 15 and 160 km, horizontal wind vector (30-160 km), ground state atomic oxygen (90-160 dynamical tracers ozone-chemistry related species (15-110 km). SMILES-2 designed fit JAXA small equipped with two...
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...
A distribution of the neutral carbon atom (C I) in Heiles cloud 2 (HCL2) has been investigated with Mount Fuji submillimeter-wave telescope. region 1.2 deg2 covering a whole HCL2 mapped 3P1-3P0 fine-structure line (492 GHz) C I. The global extent I emission is similar to that 13CO, extending from southeast northwest. However, intensity found be rather weak dense cores traced by J = 1-0 C18O. On other hand, strong observed south part which C18O fairly weak. I/CO abundance ratio greater than...
We present the first comprehensive study of physical and chemical properties quiescent starless cores L1495B L1521B, which are known to be rich in carbon-chain molecules like cyanopolyyne peak TMC-1 L1521E. have detected radio spectral lines various molecules, such as CCS, C3S, C4H, HC3N, HC5N. On other hand, NH3 weak N2H+ not detected. According our mapping observations C3S lines, dense L1521B compact, with radius 0.063 0.044 pc, respectively, a simple elliptical structure. The...
We present observations of the 3P1-3P0 fine-structure transition atomic carbon [C I], J = 3-2 CO, and 1-0 transitions 13CO C18O toward DR 15, an H II region associated with two mid-infrared dark clouds (IRDCs). The emissions closely follow patches seen in optical wavelength, showing self-gravitating molecular cores masses 2000 900 M☉, respectively, at positions cataloged IRDCs. Our data show a rough spatial correlation between I] 1-0. Bright emission occurs relatively cold gas behind but...
We have observed the four hyperfine components of 18 cm OH transition toward translucent cloud eastward Heiles Cloud 2 (HCL2E), cold dark L134N, and photodissociation region ρ-Ophiuchi molecular with Effelsberg 100 m telescope. found intensity anomalies among in all three regions. In particular, an absorption feature 1612 MHz satellite line against cosmic microwave background has been detected HCL2E two positions cloud. On basis statistical equilibrium calculations, we find that originate...
The 3P1-3P0 fine-structure line of the neutral carbon atom ([C I]) has been mapped over 18 × 13 area L1688 cloud in ρ Ophiuchi region with Mount Fuji submillimeter-wave telescope. 3P2-3P1 [C I] also observed toward two representative positions to evaluate excitation temperature lines. overall extent distribution generally resembles that 13CO distribution. major peaks; one (peak I) is at Oph A, and other II) east side C18O core southern part L1688. Peak II located beyond respect exciting star...
We present a characterization of 1.5 THz waveguide niobium titanium nitride (NbTiN) superconducting hot electron bolometer (HEB) mixer which can be pumped by commercial solid state tunable local oscillator (LO) source. The NbTiN HEB is made from 12 nm thick thin film deposited on quartz substrate at room temperature. A gold electrode formed in situ the without breaking vacuum to ensure good contact. uncorrected DSB receiver noise temperature measured 1700 K THz, whereas derived 1000 after...
We have developed the 3.1-THz heterodyne receiver using an NbTiN Hot-Electron Bolometer (HEB) mixer and a THz Quantum Cascade Laser (THz-QCL) as local oscillator. A quasi optical twin-slot antenna is adopted for coupling of RF signal with mixer. The noise temperature measured to be 5600 K in DSB. When loss corrected, it low 2100 K. This result demonstrates that HEB works equivalent level performance at 3.1 comparison NbN mixers usually employed this frequency region.
We report extreme enhancements of the nitric oxide (NO) column density observed with ground-based millimeter-wave spectroscopic radiometer installed at Syowa Station, Antarctica, during a large geomagnetic storm in April 2012. From NO spectrum line shape and relationship solar radiation, we concluded that was emitted altitude range between 75 km 100 km. The gradually increased recovery phase. In addition to variations on time frame several days, found diurnal variations. increase related...
In this paper, we present the development of waveguide niobium titanium nitride (NbTiN) superconducting hot electron bolometer (HEB) mixers, cryogenically cooled by a 4 K close-cycled refrigerator. The NbTiN thin film is formed on crystalline quartz substrate sputtering an NbTi target with Ar and N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas at room temperature. HEB mixer element fabricated using 12 nm film, mounted block....
Aims. A mapping observation of the J = 1/2 Λ-type doubling transition (3.3 GHz) CH has been conducted toward Heiles Cloud 2 (HCL2) in Taurus molecular cloud complex to reveal its cloud-scale distribution.
Niobium-titanium-nitride (NbTiN) thin films were prepared on quartz substrates by reactive dc-magnetron sputtering with a NbTi alloy target, and their properties, studied systematically. Properties of the films, such as superconducting transition temperature strongly dependent variation cathode voltage, /spl Delta/U, which is induced when small fraction N/sub 2/ added to Ar during sputter discharge. High quality high 15 K resistivity sim/100 mu//spl Omega/cm have been obtained at around...