A5044718267- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Radiation Detection and Scintillator Technologies
- Advanced Semiconductor Detectors and Materials
- Mechanics and Biomechanics Studies
- Medical Imaging Techniques and Applications
- Machine Learning in Materials Science
- Galaxies: Formation, Evolution, Phenomena
- Chalcogenide Semiconductor Thin Films
- Advanced X-ray and CT Imaging
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Particle Detector Development and Performance
- Radiation Therapy and Dosimetry
- Superconducting and THz Device Technology
- X-ray Spectroscopy and Fluorescence Analysis
- Radiopharmaceutical Chemistry and Applications
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
Osaka Health Science University
2024
Osaka University
2024
The University of Tokyo
2016-2023
Durham University
2022-2023
Kavli Institute for the Physics and Mathematics of the Universe
2019-2022
Japan Aerospace Exploration Agency
2016-2018
Institute of Space and Astronautical Science
2016-2018
1H 0707-495 is the most convincing example of a supermassive black hole with an X-ray spectrum being dominated by extremely smeared, relativistic reflection, additional requirement strongly supersoler iron abundance. However, here we show that features in its 2--10 keV are rather similar to archetypal wind source, PDS 456. We fit all spectra from using same model as used for 456, but viewed at higher inclination so absorption line broader not blueshifted. This gives good overall data...
Black hole binaries show equatorial disc winds at high luminosities, which apparently disappear during the spectral transition to low/hard state. This is also where radio jet appears, motivating speculation that both wind and are driven by different configurations of same magnetic field. However, these systems must have thermal winds, as outer clearly irradiated. We develop a predictive model absorption features from based on pioneering work Begelman, McKee & Shields. couple this realistic...
ABSTRACT New X-ray polarization results are challenging our understanding of the accretion flow geometry in black hole binary systems. Even spectra dominated by a standard disc can give unexpected results, such as high-inclination 4U 1630−472, where observed is much higher than predicted. This system also shows strong, highly ionized wind, consistent with thermal-radiative driving from outer disc, leading to speculation that scattering wind responsible for unexpectedly high degree optically...
Abstract A recent report on the detection of very-high-energy gamma rays from V4641 Sagittarii (V4641 Sgr) up to ≈0.8 PeV has made it second confirmed “PeVatron” microquasar. Here we observation Sgr with X-Ray Imaging and Spectroscopy Mission (XRISM) in 2024 September. Thanks large field view low background, CCD imager Xtend successfully detected for first time X-ray extended emission around a significance ≳4.5 σ >10 based our imaging spectral analysis, respectively. The spatial extent is...
Abstract Radio-quiet Seyfert galaxies have been detected in GeV gamma rays by the Fermi Large Area Telescope (LAT), but origin of much this emission is unclear. We consider nearby example GRS 1734−292, which exhibits weak starburst and jet activities that are insufficient to explain observed gamma-ray flux. With first detailed multiwavelength study source, we demonstrate an active galactic nucleus (AGN) disk wind can account for its emission. Using a lepto-hadronic model based on shocked...
Warm absorbers are present in many Active Galactic Nuclei (AGN), seen as mildly ionised gas outflowing with velocities of a few hundred to thousand kilometres per second. These slow imply large launch radius, pointing the broad line region and/or torus origin this material. Thermal driving was originally suggested plausible mechanism for launching material but recent work has focused instead on magnetic winds, unifying these slow, winds more highly ultra-fast outflows. Here we use recently...
Black hole accretion discs can produce powerful outflowing plasma (disc winds), seen as blue-shifted absorption lines in stellar and supermassive systems. These winds Quasars have an essential role controlling galaxy formation across cosmic time, but there is no consensus on how these are physically launched. A single unique observation of a stellar-mass black GRO J1655-40 was used to argue that magnetic driving the only viable mechanism motivated unified models both binaries Quasars. The...
Blueshifted absorption lines are seen in high inclination black hole binary systems their disc dominated states, showing these power an equatorial wind. While some contribution from magnetic winds remain a possibility, thermal and thermal-radiative expected to be present. We show results radiation hydrodynamic simulations which that the additional force atomic features (bound-free lines) important along with electron scattering. Together, increase wind velocity at inclinations, so they...
We show the best current simulations of absorption and emission features predicted from thermal-radiative winds produced X-ray illumination outer accretion disc in binary systems. use density velocity structure derived a radiation hydrodynamic code as input to Monte-Carlo transport calculation. The initial conditions are matched those black hole system H1743-322 its soft, dominated state, where wind seen Chandra grating data. Our simulation fits well observed line profile, showing that these...
Multi-isotope imaging in vivo is an appealing molecular approach that provides extensive information about pathways cannot be accessed usual methods with a single radioactive probe. However, conventional systems have limited energy resolution; as result, the images obtained from multi-isotope are associated problems, such nonnegligible noise and spectral crosstalk, owing to photons emitted radioisotopes being simultaneously used experiments. This study proposes novel small-animal SPECT...
We fit the observed high ionisation X-ray absorption lines in neutron star binary GX13+1 with a full simulation of thermal-radiative wind. This uses radiation hydrodynamic code coupled to Monte Carlo transfer compute line profiles from Hydrogen and Helium-like iron Nickel, including all strong Kα Kβ transitions. The wind is very as this object has large disc luminous. Fe are strongly saturated ion columns large, so equivalent widths (EWs) depend sensitively on velocity structure....
Elemental analysis based on muonic X-rays resulting from muon irradiation provides information about bulk material composition without causing damage, which is essential in the case of precious or otherwise unreachable samples, such as archeology and planetary science. We developed a three-dimensional (3D) elemental technique by combining method negative muons with an imaging cadmium telluride double-sided strip detector (CdTe-DSD) designed for hard X-ray soft [Formula: see text]-ray...
Blueshifted absorption lines from highly ionized iron are seen in some high inclination X-ray binary systems, indicating the presence of an equatorial disc wind. This launch mechanism is under debate, but thermal driving should be ubiquitous. irradiation central source heats surface, forming a wind outer where local escape velocity lower than sound speed. The mass-loss rate each part determined by luminosity and spectral shape source. We use these together with assumed density structure to...
Accretion disc coronae (ADC) sources are very high inclination neutron star or black hole binaries, where the outer accretion flow blocks a direct view of central source. The weak observed X-ray emission is instead produced mainly by scattering intrinsic radiation from highly ionised gas surrounding source, ADC. However, origin this material still under debate. We use ADC source 2S 0921-630 (V395 Car) to test whether it consistent with thermal-radiative wind illuminating and puffing up disc....
Abstract Metals form an essential part of the Universe at all scales. Without metals we would not exist, and look completely different. are primarily produced via nuclear processes in stars, spread out through winds or explosions, which pollute surrounding space. The wanderings in-and-out astronomical objects crucial determining their own evolution thus that as a whole. Detecting assessing relative absolute abundances energetics can be used to trace these cosmic components. scope this paper...
Radio-quiet Seyfert galaxies have been detected in GeV gamma-rays by the $Fermi$ Large Area Telescope (LAT), but origin of much this emission is unclear. We consider nearby example, galaxy GRS 1734-292, which exhibits weak starburst and jet activities that are insufficient to explain observed gamma-ray flux. With first detailed multi-wavelength study source, we demonstrate an active galactic nucleus (AGN) disk wind can account for its emission. Using a lepto-hadronic model based on shocked...
A recent report on the detection of very-high-energy gamma rays from V4641 Sagittarii (V4641 Sgr) up to ~0.8 peta-electronvolt has made it second confirmed "PeVatron" microquasar. Here we observation Sgr with X-Ray Imaging and Spectroscopy Mission (XRISM) in September 2024. Thanks large field view low background, CCD imager Xtend successfully detected for first time X-ray extended emission around a significance > 4.5 sigma 10 based our imaging spectral analysis, respectively. The spatial...
New X-ray polarisation results are challenging our understanding of the accretion flow geometry in black hole binary systems. Even spectra dominated by a standard disc can give unexpected results, such as high inclination 4U 1630- 472, where observed is much higher than predicted. This system also shows strong, highly ionised wind, consistent with thermal-radiative driving from outer disc, leading to speculation that scattering wind responsible for unexpectedly degree optically thick disc....
High-quality CdTe semiconductor detectors with both fine position resolution and high energy hold great promise to improve measurement in various hard X-ray gamma-ray imaging fields. ISAS/JAXA has been developing meet scientific demands latest celestial observation severe environmental limitation (power consumption, vibration, radiation) space for over 15 years. The of a Schottky diode In/CdTe/Pt or Al/CdTe/Pt contact is highlight our development. We can extremely reduce leakage current...
Accretion disc coronae (ADC) sources are very high inclination neutron star or black hole binaries, where the outer accretion flow blocks a direct view of central source. The weak observed X-ray emission is instead produced mainly by scattering intrinsic radiation from highly ionised gas surrounding source, ADC. However, origin this material still under debate. We use ADC source 2S 0921-630 (V395 Car) to test whether it consistent with thermal-radiative wind illuminating and puffing up disc....
Rhenium radioisotopes are very attractive for targeted radionuclide therapy. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">186</sup> Re has both beta particle emissions with properties suitable to perform therapy and photon emissions, which can be used diagnostic investigation by SPECT. Accelerator-based synthesis proton-or deuteron-induced reaction on W provide no-carrier-added Re, is difficult produce a conventional method nuclear reactors....