A5012598976- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- SAS software applications and methods
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Cancer and Skin Lesions
- RNA regulation and disease
- Seismic Waves and Analysis
- Geophysics and Sensor Technology
- Solar and Space Plasma Dynamics
- Atomic and Subatomic Physics Research
- Astrophysics and Star Formation Studies
- Medical Imaging Techniques and Applications
- High-pressure geophysics and materials
- Advanced X-ray and CT Imaging
- Cosmology and Gravitation Theories
- melanin and skin pigmentation
- Distributed and Parallel Computing Systems
Kumamoto Gakuen University
2024-2025
Fukuoka University
2017-2024
Saitama University
2024
National Astronomical Observatory of Japan
2004-2023
Aomori University
2023
Adnet Systems (United States)
2020
University of Maryland, College Park
2020
Kyoto University
2007-2016
National Institute of Technology, Kurume College
2013
University of Miyazaki
2010
The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on Japanese Experiment Module-Exposed Facility (JEM-EF) ISS. It scheduled for launch in middle 2009 monitor all-sky objects every ISS orbit. will more powerful than any previous All Sky Monitor (ASM) payloads, being able hundreds AGN. provide all sky images sources about 20 mCrab energy band 2-30 keV from observation one orbit (90 min), 4.5 day, and 1 month. A final detectability could 0.2 2...
Abstract KAGRA is a newly built gravitational-wave telescope, laser interferometer comprising arms with length of 3 km, located in Kamioka, Gifu, Japan. was constructed under the ground and it operated using cryogenic mirrors that help reducing seismic thermal noise. Both technologies are expected to provide directions for future telescopes. In 2019, finished all installations designed configuration, which we call baseline KAGRA. For this occasion, present an overview from various viewpoints...
We present observations of the unusual microlensing event OGLE 2003-BLG-235/MOA 2003-BLG-53. In this event, a short-duration (~7 days) low-amplitude deviation in light curve due to single-lens profile was observed both MOA (Microlensing Observations Astrophysics) and (Optical Gravitational Lensing Experiment) survey observations. find that features can only be reproduced using binary model with an extreme (planetary) mass ratio 0.0039 for lensing system. If lens system comprises...
Abstract The Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is a future Japanese space mission with frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection primordial gravitational waves, which could have been produced during inflationary period right after birth Universe. There are many other scientific objectives DECIGO, including direct measurement acceleration expansion Universe, and reliable accurate predictions timing locations neutron star/black hole binary...
Mobility and current drive improvements associated with biaxial tensile stress in Si n- p-MOSFETs are briefly reviewed. Electron mobility enhancements at high channel doping (up to 6 /spl times/ 10/sup 18/ cm/sup -3/) characterized strained n-MOSFETs. For low inversion layer carrier concentrations, channel-dopant ionized impurity scattering does reduce the strain-induced enhancement, but enhancement is recovered higher charge where screening efficient. also discussed. There process...
We present the Suzaku broadband observations of two AGNs detected by Swift BAT hard X-ray (>15 keV) survey that did not have previous data, SWIFT J0601.9-8636 and J0138.6-4001. The spectra reveal in both objects a heavily absorbed power-law component with column density NH ≃ 1023.5-1024 cm-2 dominates above 10 keV an intense reflection solid angle ≳2π from cold, optically thick medium. find these extremely small fraction scattered light nucleus, ≲0.5% respect to intrinsic component. This...
KAGRA is a newly built gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this series of articles, we present an overview the baseline KAGRA, for which finished installing designed configuration 2019. This article describes method calibration (CAL) used reconstructing signals from detector outputs, as well characterization (DET). We also review physical environmental monitors (PEM) system and geophysics (GIF). Both are...
DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO) is a future Japanese space gravitational-wave antenna. The most important objective of DECIGO, among various sciences to be aimed at, detect gravitational waves coming from the inflation universe. DECIGO consists four clusters spacecraft, and each cluster three spacecraft with Fabry–Perot Michelson interferometers. As pathfinder mission B-DECIGO will launched, hopefully in 2020s, demonstrate technologies necessary for as well...
We report the in-orbit performance of Gas Slit Camera (GSC) on MAXI (Monitor All-sky X-ray Image) mission carried International Space Station (ISS). Its commissioning operation started August 8, 2009, confirmed basic performances effective area in energy band 2--30 keV, spatial resolution slit-and-slat collimator and detector with 1.5 degree FWHM, source visibility 40-150 seconds for each scan cycle, sky coverage 85% per 92-minute orbital period 95% day. The gas gains read-out amplifier have...
Abstract KAGRA is a newly build gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this paper, one of series articles featuring KAGRA, we discuss the science targets projects, considering not only baseline (current design) but also its future upgrade candidates (KAGRA+) for near to middle term ($\sim$5 years).
Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is the future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at detection primordial gravitational waves, which could be produced during inflationary period right after birth universe. There are many other scientific objectives DECIGO, including direct measurement acceleration expansion universe, and reliable accurate predictions timing locations neutron star/black hole binary coalescences....
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 Various transient phenomena on a timescale ranging from seconds to days appear at unexpected sky positions in X-rays. MAXI, Monitor of All-sky X-ray Image, the International Space Station has been monitoring about 95% day and detected objects since 2009 August. Here, we describe quasi-real-time data processing systems MAXI subsequent nova-alert system find objects, present capabilities for detect events with excess fluxes ≳80 mCrab single scan transit ≳8 4 d, send prompt alert...
Abstract Twenty-three giant flares from thirteen active stars (eight RS CVn systems, one Algol system, three dMe stars, and young stellar object) were detected during the first two years of our all-sky X-ray monitoring with gas propotional counters (GSC) Monitor All-sky Image (MAXI). The observed parameters all these MAXI/GSC are found to be at upper ends for luminosity 1031–34 erg s−1 in 2–20 keV band, emission measure 1054–57 cm−3, e-folding time 1 hr 1.5 d, total radiative energy released...
Abstract KAGRA, the kilometer-scale underground gravitational-wave detector, is located at Kamioka, Japan. In April 2020, an astrophysics observation was performed KAGRA detector in combination with GEO 600 detector; this operation called O3GK. The optical configuration O3GK based on a power-recycled Fabry–Pérot–Michelson interferometer; all mirrors were set room temperature. duty factor of approximately 53%, and displacement sensitivity 1 × 10−18 ${\rm m}/\sqrt{\rm {Hz}}$ 250 Hz....
Abstract The X-Ray Imaging and Spectroscopy Mission (XRISM) is a joint mission between the Japan Aerospace Exploration Agency (JAXA) National Aeronautics Space Administration (NASA) in collaboration with European (ESA). In addition to three space agencies, universities research institutes from Japan, North America, Europe have joined contribute developing satellite onboard instruments, data-processing software, scientific observation program. XRISM successor ASTRO-H (Hitomi) mission, which...
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...
Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE 2003-BLG-219 are presented, for which peak magnification was over 500, highest yet reported. Continuous observations around enabled a sensitive search planets orbiting lens star. No were detected. Planets 1.3 times heavier than Earth excluded from more 50% projected annular region approximately 2.3 to 3.6 astronomical units surrounding star, Uranus-mass 0.9 8.7 units, and Saturn 0.2 60 units. These largest regions...
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...
We present a systematic spectral analysis with Suzaku of six active galactic nuclei (AGNs) detected in the Swift/BAT hard X-ray (15–200 keV) survey: Swift J0138.6−4001, J0255.2−0011, J0350.1−5019, J0505.7−2348, J0601.9−8636, and J1628.1−5145. This is considered to be representative sample new AGNs without information before BAT survey. find that 0.5–200 keV spectra these sources can uniformly fitted base model consisting heavily absorbed (log NH > 23.5 cm−2) transmitted components, scattered...
We analyze the Galactic bulge microlensing event MOA 2003-BLG-37. Although Einstein timescale is relatively short, tE = 43 days, light curve displays deviations consistent with parallax effects due to Earth's accelerated motion. show that χ2 surface has four distinct local minima are induced by "jerk-parallax" degeneracy, pairs of solutions having projected radii E 1.76 and 1.28 AU, respectively. This second displaying such a degeneracy first toward bulge. For both events, jerk-parallax...
The broad band spectra of two Swift/BAT AGNs obtained from Suzaku follow-up observations are studied: NGC 612 and 3081. Fitting with standard models, we find that both sources show similar characterized by a heavy absorption $N_{\rm{H}} \simeq 10^{24} \ \rm{cm}^{-2}$, the fraction scattered light is $f_{\rm{scat}} = 0.5-0.8%$, solid angle reflection component $Ω/2π= 0.4-1.1$. To investigate geometry torus, apply numerical spectral models utilizing Monte Carlo simulations Ikeda et al. (2009)...
We construct a new X-ray (2--10 keV) luminosity function of Compton-thin active galactic nuclei (AGNs) in the local universe, using first MAXI/GSC source catalog surveyed 4--10 keV band. The sample consists 37 non-blazar AGNs at $z=0.002-0.2$, whose identification is highly ($>97%$) complete. confirm trend that fraction absorbed with $N_{\rm H} > 10^{22}$ cm$^{-2}$ rapidly decreases against ($L_{\rm X}$), from 0.73$\pm$0.25 $L_{\rm X} = 10^{42-43.5}$ erg s$^{-1}$ to 0.12$\pm0.09$...