A5103463247- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Radioactivity and Radon Measurements
- Neutrino Physics Research
- Nuclear and radioactivity studies
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Graphite, nuclear technology, radiation studies
- Galaxies: Formation, Evolution, Phenomena
- Superconducting and THz Device Technology
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Particle Detector Development and Performance
- Advanced Thermodynamic Systems and Engines
- Satellite Communication Systems
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Astronomy and Astrophysical Research
- Lightning and Electromagnetic Phenomena
- Astro and Planetary Science
- Antenna Design and Optimization
- Radio Wave Propagation Studies
- Microwave Engineering and Waveguides
Ritsumeikan University
2014-2021
Osaka City University
2011-2021
National Astronomical Observatory of Japan
2003-2020
Kyoto University
2018
Nagoya University
2010-2014
Institute of Astronomy
2003-2008
The University of Tokyo
2003-2008
Nippon Medical School
1991-2006
Misato Observatory
2005-2006
Astronomical Observatory
2004
We have developed an FX-architecture digital spectro-correlator for the Atacama Compact Array (ACA) of Large Millimeter/submillimeter Array. The correlator is able to simultaneously process four pairs dual polarization signals with bandwidth 2 GHz, which are received by up sixteen antennas. It can calculate auto- and cross-correlation spectra including cross-polarization in all combinations antennas, output correlation flexible spectral configuration such as multiple frequency ranges...
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,...
The measurement of the energy spectrum ultra-high-energy cosmic rays (UHECRs) is crucial importance to clarify their origin and acceleration mechanisms. Pierre Auger Observatory in Argentina Telescope Array (TA) US have reported measurements UHECR spectra observed southern northern hemisphere, respectively. region sky accessible both Observatories ($[-15,+24]$ degrees declination) can be used cross-calibrate two spectra. Auger-TA working group was organized 2012 has been understand...
Abstract HSC 120505.09-000027.9 (J1205–0000) is one of the highest redshift ( z = 6.72) dust-reddened quasars (red quasars) known to date. We present an improved analysis Atacama Large Millimeter/submillimeter Array data [C ii ] 158 μ m line and underlying rest-frame far-infrared (FIR) continuum emission, previously reported in T. Izumi et al. (2021b), toward J1205–0000. Red are thought be a transitional phase from obscured starburst luminous blue quasar, some cases associated with massive...
The observation of minority-carrier injection-enhanced annealing radiation damage to InGa0.5P0.5/GaAs tandem solar cells is reported. Radiation resistance InGaP/GaAs as similar with GaAs-on-Ge have been confirmed 1 MeV electron irradiations. Moreover, injection under light illumination and forward bias conditions shown enhance defect in InGaP result the recovery cell properties. These results suggest that InGaP/GaAs(/Ge) multijunction InGaP-based devices great potential for space applications.
ASTE is a 10-m submillimeter telescope operating in Atacama desert northern Chile since 2002 by NAOJ and collaborators. Thanks to the excellent observing condition at site, has been producing numerous astronomical results from star forming regions, Galactic center, Magellanic clouds, nearby galaxies, galaxy clusters. There three major improvements during years 2007-2008: continuum camera "AzTEC", new SIS receiver "CATS345", wide-band spectrometer "WHSF". AzTEC 144 element bolometer array 270...
The observation of minority-carrier injection-enhanced annealing radiation-induced defects in InGaP is reported. 1-MeV electron irradiation results demonstrate superior radiation-resistance InGa0.5P0.5 solar cells compared to GaAs-on-Ge cells. Moreover, injection under forward bias conditions shown enhance defect and result the recovery cell properties. These suggest that InGaP-based devices such as InGaP/GaAs(/Ge) multijunction InGaP(As) light-emitting further improved condition.
It is well known that radon emanation affected by moisture. The models which explain can be considered to come in three types. One predict the maximum possibility of assuming uniform distribution radium a solid grain independent other two are moisture effect on emanation, but their aims different from each other. first them demonstrate theory explaining microscopic phenomena employing observed macroscopic under moist condition. second leveling-off value conditions an data dry present paper...
We present CO(J=3-2) emission observations with the Atacama Submillimeter Telescope Experiment (ASTE) toward 5' x (or 6.6 kpc at distance D = 4.5 Mpc) region of nearby barred spiral galaxy M 83. successfully resolved major structures, i.e., nuclear starburst region, bar, and inner arms in a resolution 22'' 480 pc), showing good spatial coincidence between 6 cm continuum emissions. found global luminosity L'_CO(3-2) 5.1 10^8 K km s^-1 pc^2 within observed region. also disk (0.5 < r 3.5 kpc)...
Recent observational results provide possible evidence that binary black holes (BBHs) exist in the center of giant galaxies and may merge to form a supermassive hole process their evolution. We first detected periodic flux variation on cycle 93 ± 1 days from 3 mm monitor observations elliptical galaxy 3C 66B for which an orbital motion with period 1.05 0.03 yr had been already observed. The signal being shorter than can be explained by taking into consideration Doppler-shifted modulation due...
Abstract We present aperture synthesis high-resolution ($\sim$7$^{\prime\prime}$$\times$ 3$^{\prime\prime}$) observations in CO ($J$$=$ 1–0), HCN and 95 GHz continuum emission toward the central ($\sim$1.5 kpc) region of nearby barred spiral galaxy M 83 with Nobeyama Millimeter Array. Our 1–0) mosaic map depicts presence molecular ridges along leading sides stellar bar a nuclear twin peak structure, whereas distributions that traces dense gas ($n_{\rm H_2}$$\gt$ few $\times$...
A transient-diffusion measurement method for radon diffusion coefficients in porous materials was first developed the U.S.A. To get a correct interpretation of measured data by method, more attention needs to be put on mathematical treatment which has been somewhat neglected perhaps because inherent difficulty. Strictly speaking, concentrations have interpreted mathematically as two-region problem. But, solving equations is quite difficult analytically time-dependent boundary conditions On...
The sources of ultra-high-energy cosmic rays are still unknown, but assuming standard physics, they expected to lie within a few hundred megaparsecs from us. Indeed, over cosmological distances lose energy interactions with background photons, at rate depending on their mass number and properties photonuclear photon backgrounds. universe is not homogeneous such scales, hence the distribution arrival directions reflect inhomogeneities in galaxies; shorter loss lengths, stronger anisotropies....
It is well known that radon emanation affected by moisture. The models which explain can be considered to come in three types. One predict the maximum possibility of assuming uniform distribution radium a solid grain independent other two are moisture effect on emanation, but their aims different from each other. first them demonstrate theory explaining microscopic phenomena employing observed macroscopic under moist condition. second leveling-off value conditions an data dry present paper...
Fukui et al. (2006) discovered two molecular loops in the Galactic center and argued that foot points of loops, bright spots at both ends, represent gas accumulated by falling motion along subsequent to magnetic flotation Parker instability. We have carried out sensitive CO observations toward l=356 deg a few pc resolution six rotational transitions CO; 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) C18O(J=1-0). The high image 12CO (J=3-2) has revealed detailed distribution excitation including U...
Abstract We present an $\sim 2^{\prime\prime}$ resolution image of the CO (2–1) emission and 4^{\prime\prime}$ (3–2) in $z=1.3$ hyper-luminous starburst galaxy MIPS J142824.0$+$352619, obtained at Nobeyama Radio Observatory. Our new detections yield $L'_{\mathrm{CO}\,(3 \hbox{--} 2)} = 1.4 \; (\pm 0.5) \times 10^{11}$ $L'_{\mathrm{CO}\,(2 \hbox{--}1)} 1.2 0.3) 10^{11} \,\mathrm{K} \,\mathrm{km} \,\mathrm{s}^{-1} \,\mathrm{pc}^2$, which translate to a molecular gas mass \,{{{M}_{\odot}}}$,...
Abstract Nobeyama Millimeter Array was used to observe millimeter-wave afterglow of GRB 030329 at 93 GHz and 141 from 2003 April 6 (8.23 days after the burst) May 30 (61.97 days). A sensitive search for CO $(J=1 \hbox{--} 0)$ emission/absorption host galaxy also carried out. Unresolved millimeter continuum emission position detected until 21. We found a steep decline flux ($\propto t^{-2.0}$) during this period, in accord with previous report. Moreover, our data implies that decay...
Abstract We report on a deep search for $^{12}$CO ($J$=3–2) line emission from the host galaxy of GRB 980425 with Atacama Submillimeter Telescope Experiment (ASTE). observed five points galaxy, covering entire region. After combining all spectra, we obtained global spectrum rms noise level 3.3 mK in $T_{\mathrm{mb}}$ scale at velocity resolution 10 $\mathrm{km\ s^{-1}}$. No significant was detected, though found marginal feature range corresponding to redshift galaxy. derived 3 $\sigma$...
Telescope Array (TA) is the largest ultrahigh energy cosmic-ray (UHECR) observatory in Northern Hemisphere. A surface detector (SD) array covers approximately 700 km$^2$, and SD surrounded by three fluorescence (FD) stations. TA has found evidence for a cluster of cosmic rays with energies greater than 57 EeV from data. In order to confirm this more data, we started TAx4 experiment which expands detection area using new SDs FDs. We construction are arranged square grid 2.08 km spacing at...
We have carried out 12CO(J =2-1) and =3-2) observations at spatial resolutions of 1.0-3.8 pc toward the entirety loops 1 2 part loop 3 in Galactic center with NANTEN2 ASTE. These new results revealed detailed distributions molecular gas line intensity ratio two transitions, R3-2/2-1. In three loops, R3-2/2-1 is a range from 0.1 to 2.5 peak ~ 0.7 while that disk 1.2 0.4. This supports are more highly excited than gas. An LVG analysis 12CO J =3-2 2-1 13CO =2-1, six positions shows density...
The Telescope Array (TA) collaboration has reported on an indication of the excess flux ultrahigh energy cosmic rays (UHECRs) with E > 57 EeV, located near Ursa Major cluster [1].Corresponding sky region was called "hotspot".In present work we test this result using latest data collected by TA SD array.As a result, number events in hotspot increases to 24, while expected background is 6.88 first 5-year and additional 2-year data.The statistical significance for seven year dataset remains at...
Very small pores called ‘nanopores’ play an important role in enhancement of radon emanation grains. The concept nanopores was originally proposed by Rama and Moore. present paper has evolved this into more specific grain configurations to estimate coefficients theoretical calculations. These cover combinations nanopore geometry radium distribution Radium is the parent nuclide radon. Assuming isotropic emission from its birthplace with recoil energy imparted decay radium, calculation led...
Radon emanation coefficients larger than 0.6 have been reported; such large values were unexpected. This led the authors to study how maximum possible radon coefficient (hereafter referred as 'maximum probability') could be determined. Theoretical calculations repeated in which grain configuration was changed order get probability. Two types of grains targeted. The first type consisted two components mixed together; one component a amount mother including no radium and other small very fine...
We present updated results of the search for ultra-high energy photons with primary energies greater than 10 EeV. The data Telescope Array Surface Detector collected over 11 years are used in this work. method is based on machine learning classifier, which trained both reconstructed composition-sensitive parameters event and calibrated waveform signals at each triggered station Detector.