Y. Fukui

Ibaraki University, Mito-shi, Ibaraki, Japan

Are you Y. Fukui?

Claim your profile

Publications (733)2024.8 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The results of Mopra molecular spectral line observations towards the supernova remnant HESSJ1731-347 (G353.6-0.7) and the unidentified gamma-ray source HESSJ1729-345 are presented. Dense molecular gas in three different velocity-bands (corresponding to three Galactic arms) are investigated using the CS(1-0) line. The CS-traced component provides information about the dense target material in a hadronic scenario for gamma-ray production (cosmic rays interacting with gas) and an understanding of the dynamics. Furthermore, the effects of cosmic ray diffusion into dense gas may alter the gamma-ray spectrum to cause a flattening of spectra towards such regions. Dense molecular gas mass at a level of ~10^5 Mo was revealed in this survey, with mass of the order of ~10^3 Mo towards HESSJ1729-345 in each coincident Galactic arm, but no significant detection of dense molecular gas towards HESSJ1731-347 at the currently-preferred distance of ~5.2-6.2 kpc was discovered.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have carried out 13CO (J=2-1) observations of the active star-forming region N159 West in the LMC with ALMA. We have found that the CO distribution at a sub-pc scale is highly elongated with a small width. These elongated clouds called "filaments" show straight or curved distributions with a typical width of 0.5-1.0 pc and a length of 5-10 pc. All the known infrared YSOs are located toward the filaments. We have found broad CO wings of two molecular outflows toward young high-mass stars in N159W-N and N159W-S, whose dynamical timescale is ~10^4 yrs. This is the first discovery of protostellar outflow in external galaxies. For N159W-S which is located toward an intersection of two filaments we set up a hypothesis that the two filaments collided with each other ~10^5 yrs ago and triggered formation of the high-mass star having ~37Mo. The colliding clouds show significant enhancement in linewidth in the intersection, suggesting excitation of turbulence in the shocked interface layer between them as is consistent with the magneto-hydro-dynamical numerical simulations (Inoue & Fukui 2013). This turbulence increases the mass accretion rate to ~10^-4 Mo yr^-1, which is required to overcome the stellar feedback to form the high-mass star.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: RCW120 is a Galactic HII region which has a beautiful infrared ring. Previous studies on RCW120 provided a wealth of information on the second generation star formation, but the origin of the exciting O star located inside the ring structure has not been focused so far. Our new CO observations performed with the NANTEN2, Mopra, and ASTE telescopes have revealed that two molecular clouds with a velocity separation 20km/s are both physically associated with RCW120. The cloud at -8km/s apparently traces the infrared ring, while the other cloud at -28km/s is mainly distributed just outside the opening of the infrared ring, interacting with the HII region as supported by high kinetic temperature of the molecular gas and by the complementary distribution with the ionized gas. A spherically expanding shell driven by the HII region is usually discussed as the origin of the observed ring structure in RCW120. In this model, the neutral material which surrounds the HII region is expected to have an expanding motion. Our observations, however, indicate no evidence of the expanding motion in the velocity space, being inconsistent with the expanding shell scenario. We here postulate an alternative that, by applying the model introduced by Habe & Ohta (1992), the exciting O star in RCW120 was formed by a collision between the present two clouds at a colliding velocity of ~30km/s. In the model, the observed infrared ring can be interpreted as the cavity created in the larger cloud by the collision, whose inner surface is illuminated by the strong UV radiation after the birth of the O star. We argue that the present cloud-cloud collision scenario explains the observed signatures of RCW120, i.e., its ring morphology, coexistence of the two clouds and their large velocity separation, and absence of the expanding motion.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present fully sampled ~3' resolution images of the 12CO(J=2-1), 13CO(J=2-1), and C18O(J=2-1) emission taken with the newly developed 1.85-m mm-submm telescope toward the entire area of the Orion A and B giant molecular clouds. The data were compared with the J=1-0 of the 12CO, 13CO, and C18O data taken with the Nagoya 4-m telescope and the NANTEN telescope at the same angular resolution to derive the spatial distributions of the physical properties of the molecular gas. We explore the large velocity gradient formalism to determine the gas density and temperature by using the line combinations of 12CO(J=2-1), 13CO(J=2-1), and 13CO(J=1-0) assuming uniform velocity gradient and abundance ratio of CO. The derived gas density is in the range of 500 to 5000 cm-3, and the derived gas temperature is mostly in the range of 20 to 50 K along the cloud ridge with a temperature gradient depending on the distance from the star forming region. We found the high-temperature region at the cloud edge facing to the HII region, indicating that the molecular gas is interacting with the stellar wind and radiation from the massive stars. In addition, we compared the derived gas properties with the Young Stellar Objects distribution obtained with the Spitzer telescope to investigate the relationship between the gas properties and the star formation activity therein. We found that the gas density and star formation efficiency are well positively correlated, indicating that stars form effectively in the dense gas region.
    The Astrophysical Journal Supplement Series 12/2014; 216(1). DOI:10.1088/0067-0049/216/1/18 · 14.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Diffuse $\gamma$-ray emission is the most prominent observable signature of celestial cosmic-ray interactions at high energies. While already being investigated at GeV energies over several decades, assessments of diffuse $\gamma$-ray emission at TeV energies remain sparse. After completion of the systematic survey of the inner Galaxy, the H.E.S.S. experiment is in a prime position to observe large-scale diffuse emission at TeV energies. Data of the H.E.S.S. Galactic Plane Survey are investigated in regions off known $\gamma$-ray sources. Corresponding $\gamma$-ray flux measurements were made over an extensive grid of celestial locations. Longitudinal and latitudinal profiles of the observed $\gamma$-ray fluxes show characteristic excess emission not attributable to known $\gamma$-ray sources. For the first time large-scale $\gamma$-ray emission along the Galactic Plane using imaging atmospheric Cherenkov telescopes has been observed. While the background subtraction technique limits the ability to recover modest variation on the scale of the H.E.S.S. field of view or larger, which is characteristic of the inverse Compton scatter-induced Galactic diffuse emission, contributions of neutral pion decay as well as emission from unresolved $\gamma$-ray sources can be recovered in the observed signal to a large fraction. Calculations show that the minimum $\gamma$-ray emission from $\pi^0$-decay represents a significant contribution to the total signal. This detection is interpreted as a mix of diffuse Galactic $\gamma$-ray emission and unresolved sources.
    Physical Review D 11/2014; 90(12). DOI:10.1103/PhysRevD.90.122007 · 4.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The spatial variations of the gas-to-dust ratio (GDR) provide constraints on the chemical evolution and lifecycle of dust in galaxies. We examine the relation between dust and gas at 10-50 pc resolution in the Large and Small Magellanic Clouds (LMC and SMC) based on Herschel far-infrared (FIR), H I 21 cm, CO, and Halpha observations. In the diffuse atomic ISM, we derive the gas-to-dust ratio as the slope of the dust-gas relation and find gas-to-dust ratios of 380+250-130 in the LMC, and 1200+1600-420 in the SMC, not including helium. The atomic-to-molecular transition is located at dust surface densities of 0.05 Mo pc-2 in the LMC and 0.03 Mo pc-2 in the SMC, corresponding to AV ~ 0.4 and 0.2, respectively. We investigate the range of CO-to-H2 conversion factor to best account for all the molecular gas in the beam of the observations, and find upper limits on XCO to be 6x1020 cm-2 K-1 km-1 s in the LMC (Z=0.5Zo) at 15 pc resolution, and 4x 1021 cm-2 K-1 km-1 s in the SMC (Z=0.2Zo) at 45 pc resolution. In the LMC, the slope of the dust-gas relation in the dense ISM is lower than in the diffuse ISM by a factor ~2, even after accounting for the effects of CO-dark H2 in the translucent envelopes of molecular clouds. Coagulation of dust grains and the subsequent dust emissivity increase in molecular clouds, and/or accretion of gas-phase metals onto dust grains, and the subsequent dust abundance (dust-to-gas ratio) increase in molecular clouds could explain the observations. In the SMC, variations in the dust-gas slope caused by coagulation or accretion are degenerate with the effects of CO-dark H2. Within the expected 5--20 times Galactic XCO range, the dust-gas slope can be either constant or decrease by a factor of several across ISM phases. Further modeling and observations are required to break the degeneracy between dust grain coagulation, accretion, and CO-dark H2.
    The Astrophysical Journal 11/2014; 797(2). DOI:10.1088/0004-637X/797/2/86 · 6.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the effects of supergiant shells (SGSs) and their interaction on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star-forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC 5. 12CO (J = 3-2, 1-0) and 13CO(J = 1-0) observations with the ASTE and Mopra telescopes have been carried out toward these regions. A clumpy distribution of dense molecular clumps is revealed with 7 pc spatial resolution. Large velocity gradient analysis shows that the molecular hydrogen densities (n(H2)) of the clumps are distributed from low to high density (103-105 cm–3) and their kinetic temperatures (T kin) are typically high (greater than 50 K). These clumps seem to be in the early stages of star formation, as also indicated from the distribution of Hα, young stellar object candidates, and IR emission. We found that the N48 region is located in the high column density H I envelope at the interface of the two SGSs and the star formation is relatively evolved, whereas the N49 region is associated with LMC 5 alone and the star formation is quiet. The clumps in the N48 region typically show high n(H2) and T kin, which are as dense and warm as the clumps in LMC massive cluster-forming areas (30 Dor, N159). These results suggest that the large-scale structure of the SGSs, especially the interaction of two SGSs, works efficiently on the formation of dense molecular clumps and stars.
    The Astrophysical Journal 11/2014; 796(2):123. DOI:10.1088/0004-637X/796/2/123 · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dense, star-forming gas is believed to form at the stagnation points of large-scale ISM flows, but observational examples of 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 of having formed from material accumulated at the collision zone. Combining 12CO, 13CO and C18O(J=1-0) data with new high-resolution, 3D hydrodynamical simulations of colliding supershells, we discuss the origin and nature of the GMC (G288.5+1.5), favoring a scenario in which the cloud was partially seeded by pre-existing denser material, but assembled into its current form by the action of the shells. This assembly includes the production of some new molecular gas. The GMC is well interpreted as non-self-gravitating, despite its high mass (MH2 ~ 1.7 x 10^5 Msol), and is likely pressure confined by the colliding flows, implying that self-gravity was not a necessary ingredient for its formation. Much of the molecular gas is relatively diffuse, and the cloud as a whole shows little evidence of star formation activity, supporting a scenario in which it is young and recently formed. Drip-like formations along its lower edge may be explained by fluid dynamical instabilities in the cooled gas.
    The Astrophysical Journal 11/2014; 799(1). DOI:10.1088/0004-637X/799/1/64 · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the effects of Supergiant Shells (SGSs) and their interaction on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC 5. $^{12}$CO ($J$=3-2, 1-0) and $^{13}$CO ($J$=1-0) observations with the ASTE and Mopra telescopes have been carried out towards these regions. A clumpy distribution of dense molecular clumps is revealed with 7 pc spatial resolution. Large velocity gradient analysis shows that the molecular hydrogen densities ($n({\rm H}_2)$) of the clumps are distributed from low to high density ($10^3$-$10^5$ cm$^{-3}$) and their kinetic temperatures ($T_{\rm kin}$) are typically high (greater than $50$ K). These clumps seem to be in the early stages of star formation, as also indicated from the distribution of H$\alpha$, young stellar object candidates, and IR emission. We found that the N48 region is located in the high column density HI envelope at the interface of the two SGSs and the star formation is relatively evolved, whereas the N49 region is associated with LMC 5 alone and the star formation is quiet. The clumps in the N48 region typically show high $n({\rm H}_2)$ and $T_{\rm kin}$, which are as dense and warm as the clumps in LMC massive cluster-forming areas (30 Dor, N159). These results suggest that the large-scale structure of the SGSs, especially the interaction of two SGSs, works efficiently on the formation of dense molecular clumps and stars.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Pulsar Wind Nebula (PWN) HESS J1825-137 is one of the most extended TeV PWN and its morphology is influenced by the molecular gas located north of the TeV sources. In order to refine the composition and dynamics of the cloud, we have used the telescope Mopra in the 7 and 12 mm bands. Our results highlight dense regions and also perturbations in the southern part of the dense cloud.
    10/2014; 28. DOI:10.1142/S2010194514601999
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present the first results of the new CO J = (2 − 1) observations toward the central molecular zone (CMZ) using the NANTEN2 telescope at an angular resolution of 100″. Large area coverage of 4° × 2° in l and b and a high angular resolution of 100″ enable us to investigate detailed structures of the molecular gas in the CMZ including peculiar molecular filaments perpendicularly to the Galactic plane to b > |0.5°|. The major components of the CMZ, e.g., Sgr A, Sgr B and Sgr C cloud complexes, show high CO J = (2 − 1)/J = (1 − 0) ratios around 0.9, indicating highly excited conditions of the molecular gas, while the local foreground components show less than 0.4. The molecular filaments show the typical ratios of 0.6–0.7 indicate that they are indeed located in the Galactic center.
    Proceedings of the International Astronomical Union 10/2014; 9(S303):106-108. DOI:10.1017/S1743921314000295
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present Herschel/HIFI sub-mm atomic carbon ([Ci] 3 P 1 – 3 P 0 and [Ci] 3 P 2 – 3 P 1), ionized carbon ([Cii] 2 P 3/2 – 2 P 1/2), and ionized nitrogen ([Nii] 3 P 1 – 3 P 0) line observations obtained in the frame of the Herschel Guaranteed Time HEXGAL (Herschel EXtraGALactic) key program (P. I. Rolf Güsten, MPIfR), and NANTEN2/SMART carbon monoxide (CO(J = 4 – 3)) observations of the warm gas around the Sgr A region. The spectrally resolved emission from all lines, and the corresponding line intensity ratios, show a very complex morphology. The determination of spatial and spectral (anti)correlation with known sources in the Sgr A region such as the Arched Filaments, NTF filaments, the Sickle, Quintuplet cluster, CND clouds, is ongoing work.
    Proceedings of the International Astronomical Union 10/2014; 9(S303):73-74. DOI:10.1017/S1743921314000180
  • [Show abstract] [Hide abstract]
    ABSTRACT: We carried out large–scale (4 × 2 degree) CO multi–line observations toward the central molecular zone (CMZ) in the Galactic center (GC) with the NANTEN2 4m telescope and mapped several diffuse molecular features located at relatively high Galactic latitudes above 0°.6. These high–latitude features are composed of diffuse molecular halo gas and molecular filaments according to their morphological aspects. Their high velocities and high intensity ratios between 12CO J = (2−1) and J = (1−0) clearly indicate their location in the GC, and their total mass amount to ∼10% of that of the CMZ. We discuss that magnetic field is a possible mechanism of these high–latitude molecular features lifting up toward high galactic latitude.
    Proceedings of the International Astronomical Union 10/2014; 9(S303):194-198. DOI:10.1017/S1743921314000544
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We probe the interstellar medium towards the objects Circinus X-1, a low-mass X-ray binary with relativistic jets; and the highly energetic Westerlund 2 stellar cluster, which is located towards TeV gamma-ray emission and interesting arc- and jet-like features seen in Nanten 12CO data. We have mapped both regions with the Mopra radio telescope, in 7 mm and 12 mm wavebands, looking for evidence of disrupted/dense gas caused by the interaction between high energy outflows and the ISM. Towards Westerlund 2, peaks in CS(J=1-0) emission indicate high density gas towards the middle of the arc and the endpoint of the jet; and radio recombination line emission is seen overlapping the coincident HII region RCW49. Towards Circinus X-1, 12CO(J = 1-0) Nanten data reveals three molecular clouds that lie in the region of Cir X-1. Gas parameters for each cloud are presented here.
    09/2014; 28. DOI:10.1142/S2010194514601987
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) was a suborbital experiment designed to map magnetic fields in order to study their role in star formation processes. BLASTPol made detailed polarization maps of a number of molecular clouds during its successful flights from Antarctica in 2010 and 2012. We present the next-generation BLASTPol instrument (BLAST-TNG) that will build off the success of the previous experiment and continue its role as a unique instrument and a test bed for new technologies. With a 16-fold increase in mapping speed, BLAST-TNG will make larger and deeper maps. Major improvements include a 2.5 m carbon fiber mirror that is 40% wider than the BLASTPol mirror and ~3000 polarization sensitive detectors. BLAST-TNG will observe in three bands at 250, 350, and 500 microns. The telescope will serve as a pathfinder project for microwave kinetic inductance detector (MKID) technology, as applied to feedhorn coupled submillimeter detector arrays. The liquid helium cooled cryostat will have a 28-day hold time and will utilize a closed-cycle $^3$He refrigerator to cool the detector arrays to 270 mK. This will enable a detailed mapping of more targets with higher polarization resolution than any other submillimeter experiment to date. BLAST-TNG will also be the first balloon-borne telescope to offer shared risk observing time to the community. This paper outlines the motivation for the project and the instrumental design.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Shortened abstract: Observations of the nearby Chamaeleon clouds in gamma rays with the Fermi Large Area Telescope and in thermal dust emission with Planck and IRAS have been used with the HI and CO radio data to (i) map the gas column densities in the different phases and at the dark neutral medium (DNM) transition between the HI-bright and CO-bright media; (ii) constrain the CO-to-$H_2$ conversion factor, $X_{CO}$; (iii) probe the dust properties per gas nucleon in each gas phase and spatially across the clouds. We have separated clouds in velocity in HI and CO emission and modelled the 0.4-100 GeV intensity, the dust optical depth at 353 GHz, the thermal radiance of the large grains, and an estimate of the dust extinction empirically corrected for the starlight intensity, $A_{VQ}$. The gamma-ray emissivity spectra confirm that the GeV-TeV cosmic rays uniformly permeate all gas phases up to the CO cores. The dust and cosmic rays reveal large amounts of DNM gas, with comparable spatial distributions and twice as much mass as in the CO-bright clouds. We give constraints on the HI-DNM-CO transitions and CO-dark $H_2$ fractions for separate clouds. The corrected extinction provides the best fit to the total gas traced by the gamma rays, but we find evidence for a rise in $A_{VQ}/N_H$ and a steep rise in opacity, with increasing $N_H$ and $H_2$ fraction, and with decreasing dust temperature. We observe less variations for the specific power of the grains, except for a decline by half in the CO cores. This combined information suggests grain evolution. The gamma rays and dust radiance yield consistent $X_{CO}$ estimates near $0.7\times10^{20}$ cm$^{-2}$ (K km/s)$^{-1}$. The other dust tracers yield biased values because of the grain opacity rise in the CO clouds. These results also confirm a factor of 2 difference between $X_{CO}$ estimates at pc and kpc scales.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This letter reports the discovery of a remarkably hard spectrum source, HESS J1641-463, by the High Energy Stereoscopic System (H.E.S.S.) in the very-high energy (VHE) domain. HESS J1641-463 remained unnoticed by the usual analysis techniques due to confusion with the bright nearby source HESS J1640-465. It emerged at a significance level of 8.5 standard deviations after restricting the analysis to events with energies above 4 TeV. It shows a moderate flux level of F(E > 1 TeV) = (3.64 +/- 0.44_stat +/- 0.73_sys) x 10^-13 cm^-2s-1, corresponding to 1.8% of the Crab Nebula flux above the same energy, and a hard spectrum with a photon index of Gamma = 2.07 +/- 0.11_stat +/- 0.20_sys. It is a point-like source, although an extension up to Gaussian width of sigma = 0.05 deg cannot be discounted due to uncertainties in the H.E.S.S. PSF. The VHE gamma-ray flux of HESS J1641-463 is found to be constant over the observed period when checking time binnings from year-by-year to the 28 min exposures timescales. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1. No X-ray candidate stands out as a clear association, however Chandra and XMM-Newton data reveal some potential weak counterparts. Various VHE gamma-ray production scenarios are discussed. If the emission from HESS J1641-463 is produced by cosmic ray protons colliding with the ambient gas, then their spectrum must extend up to at least a few hundred TeV. The energy released in accelerating these particles could account for the entire energy budget of the galactic cosmic ray population above a few TeV.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) is a suborbital mapping experiment designed to study the role magnetic fields play in star formation. BLASTPol has had two science flights from McMurdo Station, Antarctica in 2010 and 2012. These flights have produced thousands of polarization vectors at 250, 350 and 500 microns in several molecular cloud targets. We present the design, specifications, and progress towards the next-generation BLASTPol experiment (BLAST-TNG). BLAST-TNG will fly a 40% larger diameter primary mirror, with almost 8 times the number of polarization-sensitive detectors resulting in a factor of 16 increase in mapping speed. With a spatial resolution of 22 arcseconds and four times the field of view of BLASTPol, BLAST-TNG will bridge the angular scales between Planck's low resolution all-sky maps and ALMA's ultra-high resolution narrow fields. The new receiver has a larger cryogenics volume, allowing for a 28 day hold time. BLAST-TNG employs three arrays of Microwave Kinetic Inductance Detectors (MKIDs) with 30% fractional bandwidth at 250, 350 and 500 microns. In this paper, we will present the new BLAST-TNG instrument and science objectives.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the thermal model of the Balloon-borne Large-Aperture Submillimeter Telescope for Polarimetry (BLASTPol). This instrument was successfully flown in two circumpolar flights from McMurdo, Antarctica in 2010 and 2012. During these two flights, BLASTPol obtained unprecedented information about the magnetic field in molecular clouds through the measurement of the polarized thermal emission of interstellar dust grains. The thermal design of the experiment addresses the stability and control of the payload necessary for this kind of measurement. We describe the thermal modeling of the payload including the sun-shielding strategy. We present the in-flight thermal performance of the instrument and compare the predictions of the model with the temperatures registered during the flight. We describe the difficulties of modeling the thermal behavior of the balloon-borne platform and establish landmarks that can be used in the design of future balloon-borne instruments.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the second generation BLASTbus electronics. The primary purposes of this system are detector readout, attitude control, and cryogenic housekeeping, for balloon-borne telescopes. Readout of neutron transmutation doped germanium (NTD-Ge) bolometers requires low noise and parallel acquisition of hundreds of analog signals. Controlling a telescope's attitude requires the capability to interface to a wide variety of sensors and motors, and to use them together in a fast, closed loop. To achieve these different goals, the BLASTbus system employs a flexible motherboard-daughterboard architecture. The programmable motherboard features a digital signal processor (DSP) and field-programmable gate array (FPGA), as well as slots for three daughterboards. The daughterboards provide the interface to the outside world, with versions for analog to digital conversion, and optoisolated digital input/output. With the versatility afforded by this design, the BLASTbus also finds uses in cryogenic, thermometry, and power systems. For accurate timing control to tie everything together, the system operates in a fully synchronous manner. BLASTbus electronics have been successfully deployed to the South Pole, and flown on stratospheric balloons.

Publication Stats

7k Citations
2,024.80 Total Impact Points

Institutions

  • 2014
    • Ibaraki University
      • College of Science
      Mito-shi, Ibaraki, Japan
  • 1986–2014
    • Nagoya University
      • Solar-Terrestrial Environment Laboratory
      Nagoya, Aichi, Japan
  • 2013
    • University of Colorado at Boulder
      • Center for Astrophysics and Space Astronomy
      Boulder, Colorado, United States
  • 1992–2013
    • Osaka Prefecture University
      • • Graduate School of Science
      • • Department of Physical Science
      Sakai, Ōsaka, Japan
    • Brandeis University
      Waltham, Massachusetts, United States
  • 2012
    • James Cook University
      • Centre for Astronomy
      Townsville, Queensland, Australia
  • 1989–2011
    • Nagoya City University
      Nagoya, Aichi, Japan
  • 2010
    • California Institute of Technology
      • Jet Propulsion Laboratory
      Pasadena, California, United States
  • 2008
    • University of California, Berkeley
      • Radio Astronomy Laboratory
      Berkeley, California, United States
  • 2007
    • Netherlands Institute for Space Research, Utrecht
      Utrecht, Utrecht, Netherlands
  • 2001–2007
    • University of California, Los Angeles
      • Department of Physics and Astronomy
      Los Angeles, CA, United States
    • Brookhaven National Laboratory
      • Physics Department
      New York City, New York, United States
    • Stanford University
      • Department of Physics
      Palo Alto, California, United States
  • 2006
    • National Astronomical Observatory of Japan
      • Astronomy Data Center
      Edo, Tōkyō, Japan
  • 2005
    • Tokyo Metropolitan University
      • Department of Physics
      Edo, Tōkyō, Japan
  • 2002–2004
    • University of Florida
      • Department of Materials Science and Engineering
      Gainesville, Florida, United States
  • 2000–2002
    • Academia Sinica
      • Institute of Physics
      Taipei, Taipei, Taiwan
    • Lawrence Berkeley National Laboratory
      Berkeley, California, United States
  • 1999
    • Nishi-Harima Astronomical Observatory
      Kōbe, Hyōgo, Japan
    • Universidad de Cantabria
      Santander, Cantabria, Spain
    • University of Santiago, Chile
      • Departamento de Economía
      CiudadSantiago, Santiago Metropolitan, Chile
  • 1991–1999
    • Argonne National Laboratory
      • Division of X-ray Science
      Lemont, Illinois, United States
  • 1995
    • Harvard-Smithsonian Center for Astrophysics
      Cambridge, Massachusetts, United States
  • 1994
    • The University of Tokyo
      Tōkyō, Japan
    • Osaka University
      Suika, Ōsaka, Japan
  • 1993
    • Boston University
      Boston, Massachusetts, United States
  • 1988
    • Scuola Normale Superiore di Pisa
      Pisa, Tuscany, Italy