Ryuichi Fujimoto
A5025374739- Astrophysical Phenomena and Observations
- Superconducting and THz Device Technology
- Radio Frequency Integrated Circuit Design
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Advanced Thermodynamic Systems and Engines
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Physics of Superconductivity and Magnetism
- Spacecraft and Cryogenic Technologies
- Advancements in PLL and VCO Technologies
- Microwave Engineering and Waveguides
- X-ray Spectroscopy and Fluorescence Analysis
- Calibration and Measurement Techniques
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Solar and Space Plasma Dynamics
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Electromagnetic Compatibility and Noise Suppression
- Nuclear Physics and Applications
- Photonic and Optical Devices
- Advanced Power Amplifier Design
Institute of Space and Astronautical Science
2002-2025
Japan Aerospace Exploration Agency
1994-2025
Kanazawa University
2014-2023
Toshiba (Japan)
2007-2019
Tohoku Institute of Technology
2018
Tohoku University
2017
Tokyo Metropolitan University
2009-2016
Goddard Space Flight Center
2009-2016
SRON Netherlands Institute for Space Research
2008-2012
Mitsubishi Electric (Japan)
2012
High-sensitivity wide-band X-ray spectroscopy is the key feature of Suzaku observatory, launched on 2005 July 10. This paper summarizes spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, high-throughput telescopes, CCD cameras, non-imaging hard detector also described.
Abstract We have developed a framework for the Monte Carlo simulations of X-Ray Telescope (XRT) and X-ray Imaging Spectrometer (XIS) on board Suzaku, mainly scientific analysis spatially spectroscopically complex celestial sources. A photon-by-photon instrumental simulator is built ANL platform, which has been successfully used in ASCA data analysis. The modular structure, XRT simulation based ray-tracing library, while XIS utilizes spectral “Redistribution Matrix File” (RMF), generated...
Abstract We report an apparent detection of the C VI 4p to 1s transition line at 459 eV, during a long-term enhancement (LTE) in Suzaku north ecliptic pole observation 2005 September 2. The observed intensity is comparable that 2p 367 eV. This strong evidence for charge-exchange process. In addition, O VII, VIII, Ne X, and Mg XI lines showed clear enhancements. There are also features 750–900–eV range could be due some combination Fe L lines, higher order transitions VIII (3p 6p 1s), IX...
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by Institute Space and Astronautical Science (ISAS). will investigate physics high-energy universe performing high-resolution, high-throughput spectroscopy with moderate angular resolution. covers very wide energy range from 0.3 keV to 600 keV. allows combination band (5-80 keV) provided multilayer coating, focusing hard mirrors imaging detectors, high energy-resolution soft (0.3-12...
The ASTRO-H mission was designed and developed through an international collaboration of JAXA, NASA, ESA, the CSA. It successfully launched on February 17, 2016, then named Hitomi. During in-orbit verification phase, on-board observational instruments functioned as expected. intricate coolant refrigeration systems for soft X-ray spectrometer (SXS, a quantum micro-calorimeter) imager (SXI, CCD) also However, March 26, operations were prematurely terminated by series abnormal events mishaps...
Abstract High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of faint unidentified emission line reported in several low-resolution studies various massive systems, such as galaxies and clusters, including Perseus cluster. We have analyzed first-light observation The for based on XMM-Newton signal from large cluster sample under dark matter decay scenario is too be detectable data. However, previously 3.5 keV flux anomalously high compared sample-based...
Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine atmospheric gas motions within central 100~kpc of Perseus cluster using observations obtained with satellite. After correcting for point spread function telescope and optically thin emission lines, find that line-of-sight velocity dispersion hot is remarkably low mostly uniform. The reaches maxima approximately 200~km~s$^{-1}$ toward active galactic nucleus (AGN) AGN inflated...
The Hitomi SXS spectrum of the Perseus cluster, with $\sim$5 eV resolution in 2-9 keV band, offers an unprecedented benchmark atomic modeling and database for hot collisional plasmas. It reveals both successes challenges current codes. latest versions AtomDB/APEC (3.0.8), SPEX (3.03.00), CHIANTI (8.0) all provide reasonable fits to broad-band spectrum, are close agreement on best-fit temperature, emission measure, abundances a few elements such as Ni. For Fe abundance, APEC measurements...
We present the overall design and performance of Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array x-ray microcalorimeters at focus grazing-incidence mirror Telescope (SXT) for high-resolution spectroscopy celestial sources. was designed to achieve an energy resolution better than 7 eV over 0.3-12 keV range operate more 3 years in orbit. actual is 4-5 as demonstrated during extensive ground testing prior launch measured mass flow rate liquid helium cryogen...
The X-Ray Imaging and Spectroscopy Mission (XRISM) is the successor to 2016 Hitomi mission that ended prematurely. Like Hitomi, primary science goals are examine astrophysical problems with precise highresolution X-ray spectroscopy. XRISM promises discover new horizons in astronomy. carries a 6 x pixelized micro-calorimeter on focal plane of an mirror assembly co-aligned CCD camera covers same energy band over large field view. utilizes heritage, but all designs were reviewed. attitude orbit...
Abstract The X-Ray Spectrometer (XRS) has been designed to provide the Suzaku Observatory with non-dispersive, high-resolution X-ray spectroscopy. As designed, instrument covers energy range 0.3 12 keV, which encompasses most diagnostically rich part of band. sensor consists a 32-channel array microcalorimeters, each an resolution about 6 eV. very low temperature required for operation (60 mK) is provided by four-stage cooling system containing single-stage adiabatic demagnetization...
Abstract The soft diffuse X-ray emission of twelve fields observed with Suzaku are presented together two additional from previous analyses. All have galactic longitudes 65$^\circ $$\lt$$\ell$$\lt$ 295$^\circ $ to avoid contributions the very bright source that extends at least 30$^\circ Galactic center. surface brightnesses nine for which apparently uncontaminated ROSAT Sky Survey (RASS) were available statistically consistent RASS values, an upper limit differences 17 $\times$...
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by Institute Space and Astronautical Science (ISAS). will investigate physics high-energy universe via suite four instruments, covering very wide energy range, from 0.3 keV to 600 keV. These instruments include high-resolution, high-throughput spectrometer sensitive over 0.3-2 with high spectral resolution Delta E < 7 eV, enabled micro-calorimeter array located focal plane thin-foil...
A 60-GHz receiver (RX) front-end chip fabricated in 90 nm CMOS process is presented. The RX consists of an LNA, a downconversion mixer, and phase-locked loop synthesizer. capable generating LO signal from components the employ fully differential architecture to avoid influences parasitic operate with low amplitude. Measured power gain NF 22 dB 8.4 were obtained at 61.5 GHz, respectively, receives radio on-chip dipole antenna. These results indicate possibility realization single-chip transceiver.
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by Institute Space and Astronautical Science (ISAS), with planned launch 2015. equipped suite sensitive instruments highest energy resolution ever achieved at E > 3 keV wide range spanning four decades from soft X-rays to gamma-rays. simultaneous broad band pass, coupled high spectral Delta < 7 eV micro-calorimeter, will enable variety important science themes be pursued. expected...
Recently, short-distance high-speed wireless communication using a 60 GHz band has been studied for mobile application. To realize higher-speed while maintaining low power consumption application D (110-170 GHz) is promising since it can potentially provide wider frequency band. Thus, we have D-band CMOS circuits to low-power ultrahigh-speed communication. In the band, however, no sufficient device model provided, research generally start from modeling. this paper, design procedure...
The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. aimed to provide highest energy resolution ever achieved at E > 2 keV, using microcalorimeter instrument, cover wide range spanning four decades in from soft X-rays gamma-rays. After successful launch on 2016 February 17, spacecraft lost its function March 26, but commissioning phase for about month provided valuable...
Estimating human age from brain MR images is useful for early detection of Alzheimer's disease. In this paper we propose a fast and accurate method based on deep learning to predict subject's age. Compared with previous methods, our algorithm achieves comparable accuracy using fewer input images. With GPU version program, the time needed make prediction 20 ms. We evaluate methods mean absolute error (MAE) able MAE 4.0 years.
view Abstract Citations (128) References (59) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Simultaneous Multiwavelength Spectrum and Variability of 3C 279 from 10 9 to 24 Hz Hartman, R. C. ; Webb, J. Marscher, A. P. Travis, Dermer, D. Aller, H. M. F. Balonek, T. Bennett, K. Bloom, S. Fujimoto, Hermsen, W. Hughes, Jenkins, Kii, Kurfess, Makino, Mattox, von Montigny, Ohashi, Robson, I. Ryan, Sadun, Schoenfelder, V. Smith, G. Teraesranta, Tornikoski, Turner,...
In 1994 May, the BL Lac object PKS 2155-304 was observed continuously for ~10 days with International Ultraviolet Explorer and Extreme 2 ASCA, as well ROSAT ground-based radio, infrared, optical telescopes. The light curves show a well-defined X-ray flare followed by broader, lower amplitude extreme-ultraviolet ~1 day later broad, low-amplitude UV ~2 later. fluxes obtained at three well-separated times preceding week indicate least one previous of comparable or perhaps ongoing stochastic...
Thanks to its high spectral resolution (~5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us measure detailed structure of spatially resolved emission lines from highly ionized ions in galaxy clusters for first time. In this series papers, using SXS we have measured velocities gas motions, metallicities and multi-temperature core Perseus cluster. Here, show that when inferring physical properties line emissivities systems like Perseus, resonant scattering (RS) effect...