A5022197033- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Radio Astronomy Observations and Technology
- Advanced X-ray Imaging Techniques
- Radiation Detection and Scintillator Technologies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- High-pressure geophysics and materials
- Astro and Planetary Science
- Advanced X-ray and CT Imaging
- Ionosphere and magnetosphere dynamics
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Medical Imaging Techniques and Applications
The University of Tokyo
2016-2025
Institute of Space and Astronautical Science
2008-2024
Japan Aerospace Exploration Agency
2008-2024
Universitat de Barcelona
2023-2024
Institut d'Estudis Espacials de Catalunya
2023-2024
Aoyama Gakuin University
2011-2023
Center for Astrophysics Harvard & Smithsonian
2023
Saitama University
2008-2023
Konan University
2023
Osaka University
2023
The XIS is an X-ray Imaging Spectrometer system, consisting of state-of-the-art charge-coupled devices (CCDs) optimized for detection, camera bodies, and control electronics. Four sets sensors are placed at the focal planes grazing-incidence, nested thin-foil mirrors (XRT: X-Ray Telescope) onboard Suzaku satellite. Three have front-illuminated CCDs, while other has a back-illuminated CCD. Coupled with XRT, energy range 0.2–12 keV resolution 130 eV 5.9 keV, field view $18^\prime \times...
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.
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build next generation instrument, factor 5-10 improvement sensitivity 100 GeV 10 TeV range extension energies well below above TeV. will consist two arrays (one north, one south) for full sky coverage be operated as open observatory....
The Cherenkov Telescope Array, CTA, will be the major global observatory for very high energy gamma-ray astronomy over next decade and beyond. scientific potential of CTA is extremely broad: from understanding role relativistic cosmic particles to search dark matter. an explorer extreme universe, probing environments immediate neighbourhood black holes voids on largest scales. Covering a huge range in photon 20 GeV 300 TeV, improve all aspects performance with respect current instruments....
This White Paper, submitted to the recent ESA call for science themes define its future large missions, advocates need a transformational leap in our understanding of two key questions astrophysics: 1) How does ordinary matter assemble into scale structures that we see today? 2) do black holes grow and shape Universe? Hot gas clusters, groups intergalactic medium dominates baryonic content local Universe. To understand astrophysical processes responsible formation assembly these structures,...
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...
The northeast shell of SN 1006 is the most probable acceleration site high-energy electrons (up to ~100 TeV) with Fermi mechanism at shock front. We resolved nonthermal filaments from thermal emission in excellent spatial resolution Chandra. component extended over ~100'' (about 1 pc 1.8 kpc distance) width, consistent width derived Sedov solution. spectrum fitted a thin plasma kT = 0.24 keV nonequilibrium ionization, typical for young supernova remnant. are likely sheets scale widths ~4''...
The outer shells of young supernova remnants (SNRs) are the most plausible acceleration sites high-energy electrons with diffusive shock (DSA) mechanism. We studied spatial and spectral properties close to fronts in four historical SNRs (Cas A, Kepler's remnant, Tycho's RCW 86) excellent resolution Chandra. In all SNRs, hard X-ray emissions were found on rims which concentrate very narrow regions (so-called filaments); apparent scale widths upstream side below or order point-spread function...
Abstract Suzaku Hard X-ray Detector (HXD) achieved the lowest background level than any other previously or currently operational missions sensitive in energy range of 10–600 keV, by utilizing PIN photodiodes and GSO scintillators mounted BGO active shields to reject particle Compton-scattered events as much possible. Because it does not have an imaging capability nor rocking mode for monitor, sensitivity is limited reproducibility non (NXB) model. We modeled HXD NXB, which varies with time...
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...
We present results obtained from a series of observations the supernova remnant RX J1713.7-3946 by Suzaku satellite. The cover about two-thirds surface. successfully detected hard X-rays up to ~ 40 keV each pointing. X-ray spectra are described power-law functions with photon indices 3.0, which larger than those in energy region below 10 keV. Connection spatially-integrated XIS and HXD clearly reveals spectral cutoff 0.4--40 spectrum. This is interpreted correspond maximum acceleration...
Cosmic rays are the most energetic particles arriving at earth. Although of them thought to be accelerated by supernova remnants, details acceleration process and its efficiency not well determined. Here we show that pressure induced cosmic exceeds thermal behind northeast shock remnant RCW 86, where X-ray emission is dominated synchrotron radiation from ultra-relativistic electrons. We determined cosmic-ray content Doppler broadening measured with optical spectroscopy, combined a...
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 radioactive decay of the freshly synthesized $r$-process nuclei ejected in compact binary mergers power optical/infrared macronovae (kilonovae) that follow these events. light curves depend critically on energy partition among different products and this plays an important role estimates amount elements from a given observed signal. We study $\gamma$-ray emission decay. show $20$-$50\%$ total is released $\gamma$-rays timescales hours to month. number emitted per unit interval has...
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...
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 February 17, 2016, spacecraft lost its function March 26, but commissioning phase for about month provided valuable...
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...
We study the emission from an old supernova remnant (SNR) with age of around 10^5 yrs and that a giant molecular cloud (GMC) encountered by SNR. When SNR is yrs, proton acceleration efficient enough to emit TeV gamma-rays both at shock in GMC. The maximum energy primarily accelerated electrons so small X-rays are dominated hadronic processes, pi^0-decay synchrotron radiation secondary electrons, respectively. However, if older than several there few high-energy particles emitting because...
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...