Shoji Ogawa
A5090871618- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Fusion and Plasma Physics Studies
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Quantum Dots Synthesis And Properties
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Biofield Effects and Biophysics
- Cold Fusion and Nuclear Reactions
- Material Properties and Applications
- Medical Imaging Techniques and Applications
- Fiber-reinforced polymer composites
- Chalcogenide Semiconductor Thin Films
- Particle Accelerators and Free-Electron Lasers
- Epoxy Resin Curing Processes
- Stellar, planetary, and galactic studies
- Optical measurement and interference techniques
- Advanced X-ray and CT Imaging
- Radio Astronomy Observations and Technology
- Polymer Science and Applications
- Radioactive Decay and Measurement Techniques
Japan Aerospace Exploration Agency
2023-2025
Institute of Space and Astronautical Science
2023-2025
Kyoto University
2001-2023
Karolinska Institutet
2022
Nippon Dental University
2013-2016
Rikkyo University
1995-2014
Nagoya University
2010-2012
Toho University
2004
Nagaoka University
1993
Nagaoka University of Technology
1993
The photoluminescence intensity of ZnS–AgInS2 solid solution nanoparticles was remarkably enhanced by increasing the heating temperature to 180 °C, above which emission simply diminished, while ZnS coating particles resulted in further enhancement PL intensity, giving highest quantum yield ca. 80%.
Non-stoichiometric AgInS2 (AIS) semiconductor particles were synthesized by the thermal decomposition of single-source precursors in solutions two kinds primary amines (oleylamine and octylamine). The Ag content resulting nanoparticles was controlled adjusting chemical composition precursor used, which mole ratio Ag+ to total metal ions varied from 0.1 0.7, production non-stoichiometric AIS with varying amounts vacancies. average size slightly decreased 4.3 3.8 nm on changing solvent...
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 We present XRISM Resolve observations of the core hot, relaxed galaxy cluster Abell 2029 (A2029). find that line-of-sight bulk velocity intracluster medium (ICM) within central 180 kpc is at rest with respect to brightest galaxy, a 3 σ upper limit ∣ v < 100 km s −1 . robustly measure field-integrated ICM dispersion be = 169 ± 10 , obtaining similar results for both single-temperature and two-temperature plasma models account cool core. This result, if ascribed isotropic...
Abstract We conduct hard X-ray to radio multiwavelength spectral energy distribution (SED) decomposition for 57 local luminous and ultraluminous infrared galaxies observed with the Nuclear Spectroscopic Telescope Array and/or Swift/Burst Alert in GOALS sample. modify latest SED-fitting code X-CIGALE by implementing (IR) CLUMPY model, allowing us study torus model XCLUMPY self-consistently. Adopting parameters obtained fitting, we estimate properties of host galaxies, active galactic nucleus...
Abstract We present an initial analysis of the X-Ray Imaging and Spectroscopy Mission (XRISM) first-light observation supernova remnant (SNR) N 132D in Large Magellanic Cloud. The Resolve microcalorimeter has obtained first high-resolution spectrum 1.6–10 keV band, which contains K-shell emission lines Si, S, Ar, Ca, Fe. find that Si S are relatively narrow, with a broadening represented by Gaussian-like velocity dispersion $\sigma _v \sim 450$ km s$^{-1}$. However, Fe He$\alpha$...
Abstract We present an analysis of the first two XRISM/Resolve spectra well-known Seyfert-1.5 active galactic nucleus (AGN) in NGC 4151, obtained 2023 December. Our work focuses on nature narrow Fe K α emission line at 6.4 keV, strongest and most common X-ray observed AGN. The total is found to consist three components. Even narrowest component resolved with evident ,1 (6.404 keV) ,2 (6.391 contributions a 2:1 flux ratio, fully consistent neutral gas negligible bulk velocity. Subject...
Abstract We present the emission-line flux distributions and their ratios, as well gas outflow features, of innermost 2 kpc region type 1 Seyfert galaxy Mrk 766, using Kyoto Okayama Optical Low-dispersion Spectrograph with an optical-fiber integral field unit on Seimei Telescope. find that central 766 is kinematically disturbed, exhibiting asymmetric radially distributed active galactic nucleus (AGN)-driven ionized outflows traced by [O iii]$\lambda 5007$ velocities exceeding 500 ${\rm...
Abstract The XRISM Resolve microcalorimeter array measured the velocities of hot intracluster gas at two positions in Coma galaxy cluster: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> <mml:mi>′</mml:mi> </mml:msup> <mml:mo>×</mml:mo> </mml:math> squares center and 6 (170 kpc) to south. We find line-of-sight velocity dispersions those regions be σ z = 208 ± 12 km s −1 202 24 , respectively. central value...
Abstract We apply XCLUMPY, an X-ray spectral model from a clumpy torus in active galactic nucleus (AGN), to the broadband spectra of 10 obscured AGNs observed with both Suzaku and NuSTAR. The infrared these were analyzed by Ichikawa et al. CLUMPY code. Because XCLUMPY adopts same clump distribution as that CLUMPY, we can directly compare parameters obtained those spectra. angular widths determined ( σ IR ) are systematically larger than data X ); difference <?CDATA ${\sigma...
Abstract The location of the obscuring “torus” in an active galactic nucleus (AGN) is still unresolved issue. line widths X-ray fluorescence lines originating from torus, particularly Fe K α , carry key information on radii line-emitting regions. Utilizing XCLUMPY, clumpy torus model, we develop a realistic model emission profiles AGN where take into account broadening due to Keplerian motion around black hole. Then, apply updated best available broadband spectra (3–100 keV) Circinus galaxy...
Abstract We study “buried” active galactic nuclei (AGNs) almost fully covered by circumnuclear material in ultra/luminous infrared galaxies (U/LIRGs), which show weak ionized lines from narrow-line regions. Employing an indicator of a [O iv ] 25.89 or [Ne v 14.32 μ m line to 12 AGN luminosity ratio, we find 17 buried candidates that are ]-weak ( L IV / 12,AGN ≤ −3.0) V] −3.4) among 30 AGNs local U/LIRGs. For the AGNs, estimate their covering fractions Compton-thick (CT; N H ≥ 10 24 cm −2 )...
Abstract As an inaugural investigation under the X-ray Winds In Nearby-to-distant Galaxies (X-WING) program, we assembled a data set comprising 132 active galactic nuclei (AGNs) spanning redshifts z ∼ 0–4 characterized by blueshifted absorption lines indicative of winds. Through exhaustive review previous research, compiled outflow parameters for 583 winds, encompassing key attributes such as velocities ( V out ), ionization ξ and hydrogen column densities. By leveraging , systematically...
Abstract The X-ray binary system Cygnus X-3 (4U 2030+40, V1521 Cyg) is luminous but enigmatic owing to the high intervening absorption. High-resolution spectroscopy uniquely probes dynamics of photoionized gas in system. In this Letter, we report on an observation Cyg with XRISM/Resolve spectrometer, which provides unprecedented spectral resolution and sensitivity 2–10 keV band. We detect multiple kinematic ionization components absorption emission whose superposition leads complex line...
Abstract To investigate the origins of warm absorbers in active galactic nuclei (AGNs), we study ionization-state structure radiation-driven fountain model a low-mass AGN and calculate predicted X-ray spectra utilizing spectral synthesis code Cloudy . The show many absorption emission line features originating outflowing ionized gas. O viii 0.654 keV lines are produced mainly polar region much closer to supermassive black hole than optical narrow-line regions. measure distribution ionization...
Abstract Sagittarius A East is a supernova remnant with unique surrounding environment, as it located in the immediate vicinity of supermassive black hole at Galactic center, A$^{*}$. The X-ray emission suspected to show features overionized plasma, which would require peculiar evolutionary paths. We report on first observation X-Ray Imaging and Spectroscopy Mission (XRISM). Equipped combination high-resolution microcalorimeter spectrometer large field-of-view CCD imager, we for time...
Abstract The Imaging X-ray Polarimetry Explorer (IXPE) detected polarization in the nearest Seyfert 2 galaxy, Circinus for first time. To reproduce IXPE results, we computed degree of based on two types radiative hydrodynamic simulations: a parsec-scale three-dimensional model and sub-parsec-scale axisymmetric with higher spatial resolution. In series papers, confirmed that these models naturally explain multiwavelength observations galaxy from radio to X-rays. We used Monte Carlo Simulation...
Abstract We present the results of a systematic, broadband X-ray spectral analysis nearby active galactic nuclei (AGNs) with clumpy torus model (XCLUMPY). By adding 16 AGNs newly analyzed in this paper, we study total 28 AGNs, including unabsorbed and absorbed taken from Ichikawa et al. García-Bernete This is largest sample whose infrared spectra are by models XCLUMPY CLUMPY, respectively. The relation between Eddington ratio covering factor determined parameters each object follows trend...
Abstract We present the result of a broadband (0.5–70 keV) X-ray spectral analysis late-merger galaxy Mrk 739, which contains dual active galactic nucleus (AGN), 739E and 739W, with separation ≈3.4 kpc. The spectra obtained NuSTAR, Chandra, XMM-Newton, Swift/BAT are simultaneously analyzed by separating contributions from two AGNs extended emission Chandra data. To evaluate reflection components AGN tori, we consider models, phenomenological one (pexrav zgauss) more physically motivated...
As an inaugural investigation under the X-ray Winds In Nearby-to-distant Galaxies (X-WING) program, we assembled a dataset comprising 132 active galactic nuclei (AGNs) spanning redshifts $z \sim 0$-$4$ characterized by blueshifted absorption lines indicative of winds. Through exhaustive review previous research, compiled outflow parameters for 573 winds, encompassing key attributes such as velocities ($V_{\rm out}$), ionization ($\xi$), and hydrogen column densities. By leveraging $V_{\rm...
The X-Ray Imaging and Spectroscopy Mission (XRISM) is an international X-ray observatory developed by Japan Aerospace Exploration Agency (JAXA) National Aeronautics Space Administration (NASA) in collaboration with European (ESA), successfully launched September 2023. Since the early stage of project, XRISM science operations team (SOT) was organized independently spacecraft bus system mission instrument development teams, having prepared for in-orbit to maximize scientific outputs. During...