Y. Ueda

Kyoto University, Kioto, Kyōto, Japan

Are you Y. Ueda?

Claim your profile

Publications (686)1551.29 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this white paper we describe the prospects for ASTRO-H for the study of outflows from active galactic nuclei. The most important breakthroughs in this field are expected to arise from the high spectral resolution and sensitivity in the Fe-K band, combined with broad-band sensitivity over the full X-ray band and spectral capabilities also at lower energies. The sensitivity in the Fe-K region allows to extend the absorption measure distribution of the outflow out to the highest ionisation states accessible, where observations with current X-ray missions indicate that most of the outflowing gas is to be found. Due to the high-resolution and sensitivity it will also be able to give the definitive proof for the existence of ultra-fast outflows, and if so, characterise their physical properties in great detail. These ultra-fast outflows carry very large amounts of energy and momentum, and are of fundamental importance for feedback studies. We show how the ASTRO-H observations in general can help to constrain numerical models for outflows. The link to reflection and emission processes is also discussed, as well as the possible relation between outflows and relativistic emission lines. Finally, we discuss the prospects for other related categories of objects like BAL quasars, partially covered sources and Compton thick outflows.
    12/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: X-ray observations provide a powerful tool to probe the central engines of active galactic nuclei (AGN). A hard X-ray continuum is produced from deep within the accretion flow onto the supermassive black hole, and all optically thick structures in the AGN (the dusty torus of AGN unification schemes, broad emission line clouds, and the black hole accretion disk) "light up" in response to irradiation by this continuum. This White Paper describes the prospects for probing AGN physics using observations of these X-ray reflection signatures. High-resolution SXS spectroscopy of the resulting fluorescent iron line in type-2 AGN will give us an unprecedented view of the obscuring torus, allowing us to assess its dynamics (through line broadening) and geometry (through the line profile as well as observations of the "Compton shoulder"). The broad-band view obtained by combining all of the ASTRO-H instruments will fully characterize the shape of the underlying continuum (which may be heavily absorbed) and reflection/scattering, providing crucial constraints on models for the Cosmic X-ray Background with a subsequent impact on understanding of supermassive black hole evolution. ASTRO-H will also permit the relativistically broadened reflection spectrum from the inner accretion disk to be robustly studied, even in complex systems with, for example, warm absorption and composite soft excesses. Finally, the HXI will allow the detection and study of reverberation delays between the continuum and the Compton reflection hump from the inner disk.
    12/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Thanks to extensive observations with X-ray missions and facilities working in other wavelengths, as well as rapidly--advancing numerical simulations of accretion flows, our knowledge of astrophysical black holes has been remarkably enriched. Rapid progress has opened new areas of enquiry, including measurements of black hole spin, the properties and driving mechanisms of jets and disk winds, the impact of feedback into local environments, the origin of periodic and aperiodic X-ray variations, and the nature of super-Eddington accretion flows, among others. The goal of this White Paper is to illustrate how ASTRO-H can make dramatic progress in the study of astrophysical black holes, particularly the study of black hole X-ray binaries.
    12/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present X-ray observations of the active galactic nucleus (AGN) in NGC 4785. The source is a local Seyfert 2 which has not been studied so far in much detail. It was recently detected with high significance in the 15-60 keV band in the 66 month Swift/BAT all sky survey, but there have been no prior pointed X-ray observations of this object. With Suzaku, we clearly detect the source below 10 keV, and find it to have a flat continuum and prominent neutral iron fluorescence line with equivalent width >~1 keV. Fitting the broadband spectra with physical reflection models shows the source to be a bona fide Compton thick AGN with Nh of at least 2x10^{24} cm^{-2} and absorption-corrected 2-10 keV X-ray power L(2-10) ~ few times 10^{42} erg s^{-1}. Realistic uncertainties on L(2-10) computed from the joint confidence interval on the intrinsic power law continuum photon index and normalization are at least a factor of 10. The local bona fide Compton thick AGN population is highly heterogeneous in terms of WISE mid-infrared source colours, and the nucleus of NGC 4785 appears especially sub-dominant in the mid-infrared when comparing to other Compton thick AGN. Such sources would not be easily found using mid-infrared selection alone. The extent of host galaxy extinction to the nucleus is not clear, though NGC 4785 shows a complex core with a double bar and inner disk, adding to the list of known Compton thick AGN in barred host galaxies.
    08/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We explore the relationships between the 3.3 {\mu}m polycyclic aromatic hydrocarbon (PAH) feature and active galactic nucleus (AGN) properties of a sample of 54 hard X-ray selected bright AGNs, including both Seyfert 1 and Seyfert 2 type objects, using the InfraRed Camera (IRC) on board the infrared astronomical satellite AKARI. The sample is selected from the 9-month Swift/BAT survey in the 14-195 keV band and all of them have measured X-ray spectra at $E \lesssim 10$ keV. These X-ray spectra provide measurements of the neutral hydrogen column density ($N_{\rm H}$) towards the AGNs. We use the 3.3 {\mu}m PAH luminosity ($L_{\rm 3.3{\mu}m}$) as a proxy for star formation activity and hard X-ray luminosity ($L_{\rm 14-195keV}$) as an indicator of the AGN activity. We search for possible difference of star-formation activity between type 1 (un-absorbed) and type 2 (absorbed) AGNs. We have made several statistical analyses taking the upper-limits of the PAH lines into account utilizing survival analysis methods. The results of our $\log(L_{\rm 14-195keV})$ versus $\log(L_{\rm 3.3{\mu}m})$ regression shows a positive correlation and the slope for the type 1/unobscured AGNs is steeper than that of type 2/obscured AGNs at a $3\sigma$ level. Also our analysis show that the circum-nuclear star-formation is more enhanced in type 2/absorbed AGNs than type 1/un-absorbed AGNs for low X-ray luminosity/low Eddington ratio AGNs, while there is no significant dependence of star-formation activities on the AGN type in the high X-ray luminosities/Eddington ratios.
    Publications- Astronomical Society of Japan 08/2014; · 2.01 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent X-ray observations show absorbing winds with velocities up to mildly-relativistic values of the order of ~0.1c in a limited sample of 6 broad-line radio galaxies. They are observed as blue-shifted Fe XXV-XXVI K-shell absorption lines, similarly to the ultra-fast outflows (UFOs) reported in Seyferts and quasars. In this work we extend the search for such Fe K absorption lines to a larger sample of 26 radio-loud AGNs observed with XMM-Newton and Suzaku. The sample is drawn from the Swift BAT 58-month catalog and blazars are excluded. X-ray bright FR II radio galaxies constitute the majority of the sources. Combining the results of this analysis with those in the literature we find that UFOs are detected in >27% of the sources. However, correcting for the number of spectra with insufficient signal-to-noise, we can estimate that the incidence of UFOs is this sample of radio-loud AGNs is likely in the range f=(50+/-20)%. A photo-ionization modeling of the absorption lines with XSTAR allows to estimate the distribution of their main parameters. The observed outflow velocities are broadly distributed between v_out<1,000 km s^-1 and v_out~0.4c, with mean and median values of v_out~0.133c and v_out~0.117c, respectively. The material is highly ionized, with an average ionization parameter of log\xi~4.5 erg s^-1 cm, and the column densities are larger than N_H > 10^22 cm^-2. Overall, these characteristics are consistent with the presence of complex accretion disk winds in a significant fraction of radio-loud AGNs and demonstrate that the presence of relativistic jets does not preclude the existence of winds, in accordance with several theoretical models.
    Monthly Notices of the Royal Astronomical Society 06/2014; 443(3). · 5.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report on the results from Suzaku observations of the Galactic black hole X-ray binary H1743–322 in the low/hard state during its outburst in 2012 October. We appropriately take into account the effects of dust scattering to accurately analyze the X-ray spectra. The time-averaged spectra in the 1-200 keV band are dominated by a hard power-law component of a photon index of 1.6 with a high-energy cutoff at 60 keV, which is well described with the Comptonization of the disk emission by the hot corona. We estimate the inner disk radius from the multi-color disk component, and find that it is 1.3-2.3 times larger than the radius in the high/soft state. This suggests that the standard disk was not extended to the innermost stable circular orbit. A reflection component from the disk is detected with R = Ω/2π 0.6 (Ω is the solid angle). We also successfully estimate the stable disk component independent of the time-averaged spectral modeling by analyzing short-term spectral variability on a ~1 s timescale. A weak low-frequency quasi-periodic oscillation at 0.1-0.2 Hz is detected, whose frequency is found to correlate with the X-ray luminosity and photon index. This result may be explained by the evolution of the disk truncation radius.
    The Astrophysical Journal 06/2014; 789(2):100. · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The magnetism of magnetoelectric $S$ = 3/2 pyroxenes LiCrSi$_2$O$_6$ and LiCrGe$_2$O$_6$ is studied by density functional theory (DFT) calculations, quantum Monte Carlo (QMC) simulations, neutron diffraction, as well as low-field and high-field magnetization measurements. In contrast with earlier reports, we find that the two compounds feature remarkably different, albeit non-frustrated magnetic models. In LiCrSi$_2$O$_6$, two relevant exchange integrals, $J_1 \simeq$ 9 K along the structural chains and $J_{\text{ic1}}$ $\simeq$ 2 K between the chains, form a 2D anisotropic honeycomb lattice. In contrast, the spin model of LiCrGe$_2$O$_6$ is constituted of three different exchange couplings. Surprisingly, the leading exchange $J_{\text{ic1}}$ $\simeq$ 2.3 K operates between the chains, while $J_1$ $\simeq$ 1.2 K is about two times smaller. The additional interlayer coupling $J_{\text{ic2}}$ $\simeq$ $J_1$ renders this model 3D. QMC simulations reveal excellent agreement between our magnetic models and the available experimental data. Underlying mechanisms of the exchange couplings, magnetostructural correlations, as well as implications for other pyroxene systems are discussed.
    02/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: X-ray surveys have revealed a new class of active galactic nuclei (AGN) with a very low observed fraction of scattered soft X-rays, f_scat < 0.5%. Based on X-ray modeling these "X-ray new-type", or low observed X-ray scattering (hereafter:"low-scattering") sources have been interpreted as deeply-buried AGN with a high covering factor of gas. In this paper we address the questions whether the host galaxies of low-scattering AGN may contribute to the observed X-ray properties, and whether we can find any direct evidence for high covering factors from the infrared (IR) emission. We find that X-ray low-scattering AGN are preferentially hosted by highly-inclined galaxies or merger systems as compared to other Seyfert galaxies, increasing the likelihood that the line-of-sight toward the AGN intersects with high columns of host-galactic gas and dust. Moreover, while a detailed analysis of the IR emission of low-scattering AGN ESO 103-G35 remains inconclusive, we do not find any indication of systematically higher dust covering factors in a sample of low-scattering AGN based on their IR emission. For ESO 103-G35, we constrained the temperature, mass and location of the IR emitting dust which is consistent with expectations for the dusty torus. However, a deep silicate absorption feature probably from much cooler dust suggests an additional screen absorber on larger scales within the host galaxy. Taking these findings together, we propose that the low f_scat observed in low-scattering AGN is not necessarily the result of circumnuclear dust but could originate from interference of host-galactic gas with a column density of the order of 10^22 cm^-2 with the line-of-sight. We discuss implications of this hypothesis for X-ray models, high-ionization emission lines, and observed star-formation activity in these objects.
    Monthly Notices of the Royal Astronomical Society 11/2013; 438(1). · 5.23 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The X-ray Baldwin effect is the inverse correlation between the equivalent width (EW) of the narrow component of the iron Kα line and the X-ray luminosity of active galactic nuclei (AGN). A similar trend has also been observed between Fe Kα EW and the Eddington ratio (λEdd). Using Chandra/High Energy Grating results of Shu et al. and bolometric corrections we study the relation between EW and λEdd, and find that log EW = ( - 0.13 ± 0.03)log λEdd + 1.47. We explore the role of the known positive correlation between the photon index of the primary X-ray continuum Γ and λEdd on the X-ray Baldwin effect. We simulate the iron Kα line emitted by populations of unabsorbed AGN considering three different geometries of the reflecting material: toroidal, spherical-toroidal and slab. We find that the Γ-λEdd correlation cannot account for the whole X-ray Baldwin effect, unless a strong dependence of Γ on λEdd, such as the one recently found by Risaliti et al. and Jin et al., is assumed. No clear correlation is found between EW and Γ. We conclude that a good understanding of the slope of the Γ-λEdd relation is critical to assess whether the trend plays a leading or rather a marginal role in the X-ray Baldwin effect.
    Monthly Notices of the Royal Astronomical Society 11/2013; 435(3):1840-1851. · 5.23 Impact Factor
  • International Journal of Cardiology 10/2013; · 6.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the observation of an extraordinary luminous soft X-ray transient, MAXI J0158-744, by the Monitor of All-sky X-ray Image (MAXI) on 2011 November 11. This transient is characterized by a soft X-ray spectrum, a short duration (1.3 x 10^3 s < \Delta T_d < 1.10 x 10^4 s), a very rapid rise (< 5.5 x 10^3 s), and a huge peak luminosity of 2 x 10^40 erg s^-1 in 0.7-7.0 keV band. With Swift observations and optical spectroscopy from the Small and Moderate Aperture Research Telescope System (SMARTS), we confirmed that the transient is a nova explosion, on a white dwarf in a binary with a Be star, located near the Small Magellanic Cloud. An extremely early turn-on of the super-soft X-ray source (SSS) phase (< 0.44 d), the short SSS phase duration of about one month, and a 0.92 keV neon emission line found in the third MAXI scan, 1296 s after the first detection, suggest that the explosion involves a small amount of ejecta and is produced on an unusually massive O-Ne white dwarf close to, or possibly over, the Chandrasekhar limit. We propose that the huge luminosity detected with MAXI was due to the fireball phase, a direct manifestation of the ignition of the thermonuclear runaway process in a nova explosion.
    The Astrophysical Journal 10/2013; 779(2). · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Magnetic susceptibility and specific heat measurements on quasicrystalline approximants Au-Si-Gd and Au-Ge-Gd reveal that a ferromagnetic (FM) transition occurs at Tc = 22.5(5) K for Au-Si-Gd and at Tc = 13(1) K for Au-Ge-Gd, which are the first examples of ferromagnetism in crystalline approximants. In addition, a re-entrant spin-glass (RSG) transition is observed at TRSG = 3.3 K for Au-Ge-Gd in contrast to Au-Si-Gd. The different behaviors are understood based on the recent structural models reported by Gebresenbut et al (2013 J. Phys.: Condens. Matter 25 135402). The RSG transition in Au-Ge-Gd is attributed to a random occupation of the center of the Gd12 icosahedron by Gd atoms; a central Gd spin hinders the long-range FM order.
    Journal of Physics Condensed Matter 09/2013; 25(42):426004. · 2.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have studied surface electronic structure and light illumination effect of spinel-type MgTi2O4 with Ti3+(d1) electronic configuration. Ti4+ species are found at surfaces of MgTi2O4, which show photo-induced effect similar to the Ti4+-oxide semiconductors with surface depletion layer. MgTi2O4 with the surface Ti4+ states reacts with water for H2 emission, which is largely enhanced by light illumination.
    APL MATERIALS. 08/2013; 1(2).
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present the luminosity dwell-time distributions during the hard states of two low-mass X-ray binaries containing a neutron star (NS), 4U 1608–52 and Aql X-1, observed with MAXI/GSC. The luminosity distributions show a steep cutoff on the low-luminosity side at ~1.0 × 1036 erg s–1 in both sources. The cutoff implies a rapid luminosity decrease in their outburst decay phases and this decrease can be interpreted as being due to the propeller effect. We estimate the surface magnetic field of 4U 1608–52 to be (0.5-1.6) × 108 G and Aql X-1 to be (0.6-1.9) × 108 G from the cutoff luminosity and apply the same propeller mechanism to the similar rapid luminosity decrease observed in the transient Z source, XTE J1701–462, with RXTE/ASM. Assuming that the spin period of the NS is on the order of milliseconds, the observed cutoff luminosity implies a surface magnetic field on the order of 109 G.
    The Astrophysical Journal 08/2013; 773(2):117. · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the luminosity dwell-time distributions during the hard states of low-mass X-ray binaries containing a neutron star, 4U 1608-52 and AqlX-1, observed with MAXI/GSC. The luminosity distributions show a steep cut-off in the low-luminosity side at $\sim1.0 \times 10^{36}$ erg s$^{-1}$ in both the two sources. The cut-off implies a rapid luminosity decrease in their outburst decay phases, and the feature can be interpreted as due the propeller effect. We estimated the surface magnetic field of the neutron star to be (0.5--1.6) $\times 10^8$ G in 4U 1608-52 and (0.6--1.9) $\times 10^8$ G in AqlX-1 from the cut-off luminosity. We applied the same propeller mechanism to the similar rapid luminosity decrease observed in the transient Z-source, XTE J1701-462, with RXTE/ASM. Assuming that spin period of the neutron star is in the order of milliseconds, the observed cut-off luminosity deduces surface magnetic field in the order of $10^9$ G.
    06/2013;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the discovery of a reflection-dominated active galactic nucleus (AGN) in the early-type radio-quiet galaxy ESO 565--G019 with Suzaku and Swift/BAT. The source X-ray spectrum below 10 keV is characteristic of other Compton-thick (CT) AGN, clearly showing an inverted continuum and prodigious fluorescence iron emission above ~3 keV. A Compton shoulder to the neutral Fe Kalpha line also appears to be present. There is evidence for long-term hard X-ray flux variability which we associate with changes in the intrinsic AGN power-law. The increasing sensitivity of ongoing and new hard X-ray surveys means that more such reflection-dominated AGN ought to be uncovered in the near future. ESO 565--G019 is hosted in an early-type galaxy whose morphology has been variously classified as either type E or type S0. Only about 20 bona fide CT-AGN have been identified in the local universe so far, and all exist in host galaxies with late Hubble types (S0 or later). CT columns of nuclear obscuring gas are uncommon in early-type galaxies in the local universe, so confirmation of the exact morphological class of ESO 565--G019 is important. Infrared photometry also shows the presence of large quantities of cool dust in the host, indicative of significant ongoing star-formation. ESO 565--G019 may be the first identified local example of minor-merger driven CT-AGN growth in an early-type host, or may be the result of interaction with its neighboring galaxy ESO 565--G018 in a wide pair.
    The Astrophysical Journal 05/2013; 773(1). · 6.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present an investigation into how well the properties of the accretion flow onto a supermassive black hole may be coupled to those of the overlying hot corona. To do so, we specifically measure the characteristic spectral index, Gamma, of a power-law energy distribution, over an energy range of 2 to 10 keV, for X-ray selected, broad-lined radio-quiet AGN up to z~2 in COSMOS and E-CDF-S. We test the previously reported dependence between Gamma and black hole mass, FWHM and Eddington ratio using a sample of AGN covering a broad range in these parameters based on both the Mg ii and H-alpha emission lines with the later afforded by recent near infrared spectroscopic observations using Subaru/FMOS. We calculate the Eddington ratios, lambda_Edd, for sources where a bolometric luminosity (L_Bol) has been presented in the literature, based on SED fitting, or, for sources where these data do not exist, we calculate L_Bol using a bolometric correction to the LX, derived from a relationship between the bolometric correction, and LX/L3000. From a sample of 69 X-ray bright sources (>250 counts), where Gamma can be measured with greatest precision, with an estimate of L_Bol, we find a statistically significant correlation between Gamma and lambda_Edd, which is highly significant with a chance probability of 6.59x10^-8. A statistically significant correlation between Gamma and the FWHM of the optical lines is confirmed, but at lower significance than with lambda_Edd indicating that lambda_Edd is the key parameter driving conditions in the corona. Linear regression analysis reveals that Gamma=(0.32+/-0.05)log10 lambda_Edd+(2.27+/-0.06) and Gamma=(-0.69+/-0.11)log10(FWHM/km/s)+(4.44+/-0.42). Our results on Gamma-lambda_Edd are in very good agreement with previous results. (ABRIDGED)
    Monthly Notices of the Royal Astronomical Society 05/2013; 433(3). · 5.23 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: By means of thermodynamic and magnetic resonance measurements the S = 1/2 dimer system BaVSi2O7 is characterized. A broad maximum in the temperature dependence of the magnetic susceptibility and a Schottky-type anomaly in the specific heat allows estimating the main exchange interaction within V4+-V4+ dimers as J=37±1 K. This estimation is confirmed by pulsed magnetic field measurements of the magnetization, which is evidenced by the field-induced singlet-triplet transition at about 27 T. Both X-band and high-field terahertz electron spin resonance data qualitatively agree with the results of the specific heat and magnetization measurements. The electronic structure calculations, by using local density approximation, indicate that the magnetic properties of BaVSi2O7 can be interpreted within the weakly interacting dimer model.
    Physical Review B 04/2013; 87:134412. · 3.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present observations of a transient He-like Fe K alpha absorption line in Suzaku observations of the black hole binary Cygnus X-1 on 2011 October 5 near superior conjunction during the high/soft state, which enable us to map the full evolution from the start and the end of the episodic accretion phenomena or dips for the first time. We model the X-ray spectra during the event and trace their evolution. The absorption line is rather weak in the first half of the observation, but instantly deepens for ~10 ks, and weakens thereafter. The overall change in equivalent width is a factor of ~3, peaking at an orbital phase of ~0.08. This is evidence that the companion stellar wind feeding the black hole is clumpy. By analyzing the line with a Voigt profile, it is found to be consistent with a slightly redshifted Fe XXV transition, or possibly a mixture of several species less ionized than Fe XXV. The data may be explained by a clump located at a distance of ~10^(10-12) cm with a density of ~10^((-13)-(-11)) g cm^-3, which accretes onto and/or transits the line-of-sight to the black hole, causing an instant decrease in the observed degree of the ionization and/or an increase in density of the accreting matter. Continued monitoring for individual events with future X-ray calorimeter missions such as ASTRO-H and AXSIO will allow us to map out the accretion environment in detail and how it changes between the various accretion states.
    The Astrophysical Journal Letters 04/2013; 767(2). · 5.60 Impact Factor

Publication Stats

6k Citations
1,551.29 Total Impact Points

Institutions

  • 1974–2014
    • Kyoto University
      • • Department of Astronomy
      • • Department of Physics II
      • • Division of Chemistry
      • • Graduate School of Medicine / Faculty of Medicine
      • • Department of Geriatric Medicine
      • • Research Reactor Institute
      Kioto, Kyōto, Japan
  • 2013
    • University of Maryland, College Park
      • Department of Astronomy
      Maryland, United States
  • 1988–2013
    • The University of Tokyo
      • • Laboratory for Materials Design and Characterization
      • • Institute for Solid State Physics
      Edo, Tōkyō, Japan
  • 2012
    • Universität Augsburg
      • Institute of Physics
      Augsberg, Bavaria, Germany
  • 1998–2012
    • Hiroshima University
      • • Graduate School of Science
      • • Department of Biomaterials Science
      Hirosima, Hiroshima, Japan
    • University of Birmingham
      Birmingham, England, United Kingdom
    • Universities Space Research Association
      Houston, Texas, United States
  • 1997–2012
    • Kure National College of Technology
      Kure, Hiroshima, Japan
  • 2011
    • Pennsylvania State University
      • Department of Astronomy and Astrophysics
      University Park, MD, United States
  • 2001–2011
    • University of Cologne
      • II. Institute of Physics
      Köln, North Rhine-Westphalia, Germany
    • Tokyo Institute of Technology
      • Department of Physics
      Edo, Tōkyō, Japan
    • University Hospital Frankfurt
      Frankfurt, Hesse, Germany
  • 2010
    • Japan Atomic Energy Agency
      • Quantum Beam Science Directorate
      Muramatsu, Niigata-ken, Japan
  • 2009
    • National Institute of Advanced Industrial Science and Technology
      • Advanced Manufacturing Research Institute
      Tsukuba, Ibaraki, Japan
    • University of Virginia
      • Department of Physics
      Charlottesville, VA, United States
  • 1992–2007
    • Kanazawa Medical University
      • • Department of Radiology
      • • Medical Research Institute
      • • Department of Pathology
      Kanazawa, Ishikawa, Japan
  • 2006
    • The University of Tokushima
      • Faculty of Engineering
      Tokusima, Tokushima, Japan
    • Yamaguchi University
      • Faculty of Engineering
      Yamaguti, Yamaguchi, Japan
    • Universität Stuttgart
      Stuttgart, Baden-Württemberg, Germany
  • 2005
    • High Energy Accelerator Research Organization
      • Institute of Materials Structure Science
      Tsukuba, Ibaraki-ken, Japan
    • Okayama University
      • Department of Physics
      Okayama, Okayama, Japan
  • 2004
    • University Joseph Fourier - Grenoble 1
      Grenoble, Rhône-Alpes, France
  • 2003
    • University of Groningen
      • Materials Science Group
      Groningen, Province of Groningen, Netherlands
  • 2002
    • Moscow State Textile University
      Moskva, Moscow, Russia
    • KU Leuven
      • Section of Theoretical Physics
      Leuven, VLG, Belgium
  • 1978–2001
    • Institut Laue-Langevin
      Grenoble, Rhône-Alpes, France
  • 2000
    • Chiba University
      • Department of Physics
      Tiba, Chiba, Japan
    • NASA
      Washington, West Virginia, United States
  • 1988–1998
    • Kanazawa University
      • • Department of Orthopedic Surgery
      • • Department of Orthopaedic Surgery
      • • School of Medicine
      Kanazawa, Ishikawa, Japan
  • 1994–1997
    • Otto-von-Guericke-Universität Magdeburg
      • • Faculty of Medicine and University Clinic Magdeburg
      • • Institute for Pathology
      Magdeburg, Saxony-Anhalt, Germany
  • 1990–1996
    • Tokuyama College of Technology
      Kakuyama, Yamaguchi, Japan
  • 1995
    • Tenri Yorozu Hospital
      Тэнри, Nara, Japan
  • 1991–1993
    • University of Münster
      • Gerhard-Domagk-Institute of Pathology
      Münster, North Rhine-Westphalia, Germany
    • Himeji Institute of Technology
      Himezi, Hyōgo, Japan