A5091805102- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- SAS software applications and methods
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Statistical and numerical algorithms
- Stellar, planetary, and galactic studies
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Mechanics and Biomechanics Studies
- Advanced X-ray and CT Imaging
- Advanced X-ray Imaging Techniques
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Astro and Planetary Science
- X-ray Spectroscopy and Fluorescence Analysis
- CCD and CMOS Imaging Sensors
RIKEN
2015-2024
Nitto RIKEN (Japan)
2007-2024
Nippon Soken (Japan)
1999-2024
RIKEN Advanced Science Institute
2011-2023
Pioneer (Japan)
2021-2022
Pioneer (United States)
2020
Astrobiology Center
2019
Tokyo Institute of Technology
2010-2011
University of Miyazaki
2010
Kyoto University
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...
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
A high spectral resolution observation of the diffuse X-ray background in 60-1000 eV energy range has been made using an array 36 1 mm2 microcalorimeters flown on a sounding rocket. Detector ranged from 5 to 12 FWHM, and composite spectrum ~1 sr centered at l = 90°, b +60° was obtained with net ~9 eV. The target area includes bright keV regions but avoids Loop I North Polar Spur. Lines C VI, O VII, VIII are clearly detected intensities 5.4 ± 2.3, 4.8 0.8, 1.6 0.4 photons cm-2 s-1 sr-1,...
The Gas Imaging Spectrometer (GIS) system on board ASCA is described. experiment consists of 2 units imaging gas scintillation proportional counters with a sealed-off cell equipped an phototube. performance characterized by the high X-ray sensitivity (from 0.7 keV to over 10 keV), good energy resolution (7.8% FWHM at 6 following E−0.5 as function E), moderate position (0.5 mm dependence), fast time down 61 μs, and effective area 50 diameter. on-board signal processing data transmitted ground...
The in-orbit performance and calibration of the Gas Imaging Spectrometer (GIS), located on focal plane X-ray astronomy satellite ASCA, are described. An extensive has confirmed its basic performance, including a position resolution 0.6 mm (FWHM) an energy 7.8% (FWHM), both at 6 keV. When combined with telescope, GIS sensitivity range becomes 0.7-10 non background been to be as low (5-9) × 10−4 cs−1 cm−2 keV−1 over 1-10 keV range. long-term detector gain stable within few % for nearly 3...
We report the polarization measurement in prompt $\gamma$-ray emission of GRB 100826A with Gamma-Ray Burst Polarimeter (GAP) aboard small solar power sail demonstrator IKAROS. detected firm change angle (PA) during 99.9% ($3.5 \sigma$) confidence level, and average degree ($\Pi$) $27 \pm 11$% 99.4% ($2.9 level. Here quoted errors are given at 1 $\sigma$ level for two parameters interest. The systematic have been carefully included this analysis, unlike any previous reports. Such a high $\Pi$...
We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and 110721A, observed with the burst polarimeter (GAP) on borad IKAROS solar sail mission. detected linear signals from each degree Π = 70 ± 22% statistical significance 3.7σ for 110301A, 84+16− 28% 3.3σ confidence level 110721A. did not detect any significant change angle. These events had shorter durations dimmer brightness compared 100826A, which showed a angle, as reported Yonetoku et al....
Abstract The Gas Slit Camera (GSC) is an X-ray instrument on the MAXI (Monitor of All-sky Image) mission aboard International Space Station. It designed to scan entire sky every 92-minute orbital period in 2–30 keV band and achieve highest sensitivity among all-sky monitors ever flown so far. GSC employs large-area position-sensitive proportional counters with a total detector area 5350 cm $^2$. on-board data processor has functions format telemetry as well control high voltage protect them...
The Ginga X-ray spectra of the two binary pulsars, 4U 1907+09 and Vela X-1, were analyzed for effects due to electron cyclotron resonance. For this purpose, a new continuum spectral model, called NPEX, was developed. NPEX combined with classical scattering line profile, first tested against (typically in 2-50 keV) Her 0115+63, 1538-52, X0331+53, Cep X-4 confirmed reproduce successfully their overall including previously known resonance features. Through application same model...
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...
The recurrent hard pulsating X-ray transient X0115+63 was observed with BeppoSAX on 1999 March 19, when the source at a 2-10 keV flux level of ~310 mcrab. We report high-energy spectrum source, concentrating cyclotron resonant scattering features. is strongly pulse phase dependent, and absorption features are detected virtually all phases. In particular, four absorption-like 12.74, 24.16, 35.74, 49.5 in descending edge main peak profile. ratios between centroid energies lines respect to...
The small solar power sail demonstrator "IKAROS" is a Japanese engineering verification spacecraft launched by H-IIA rocket on May 21, 2010 at JAXA Tanegashima Space Center. IKAROS has huge with 20 m in diameter which made of thin polyimide membrane. This converts the radiation-pressure into propulsion force and accelerates spacecraft. Gamma-Ray Burst Polarimeter (GAP) aboard first polarimeter to observe gamma-ray polarization Bursts (GRBs) during cruising phase. GAP tinny detector 3.8 kg...
We report the strictest observational verification of CPT invariance in photon sector, as a result gamma-ray polarization measurement distant bursts (GRBs), which are brightest stellar-size explosions universe. detected three GRBs with high significance, and source distances may be constrained by well-known luminosity indicator for GRBs. For Lorentz- CPT-violating dispersion relation E_{\pm}^2=p^2 \pm 2\xi p^3/M_{Pl}, where denotes different circular states photon, parameter \xi is...
view Abstract Citations (103) References (47) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS GINGA Observations of Centaurus X-3 Nagase, F. ; Corbet, R. H. D. Day, C. S. Inoue, Takeshima, T. Yoshida, K. Mihara, Attention is given to a series observations made with Ginga on March 22-24, 1989, over complete orbital cycle. The data set includes preeclipse dip, the eclipse ingress and egress, itself, phase high steady emission after egress. mideclipse ephemeris...
view Abstract Citations (114) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Discovery of a Prominent Cyclotron Absorption Feature from the Transient X-Ray Pulsar X0331+53 Makishima, K. ; Mihara, T. Ishida, M. Ohashi, Sakao, Tashiro, Tsuru, Kii, Makino, F. Murakami, Nagase, Tanaka, Y. Kunieda, H. Tawara, Kitamoto, S. Miyamoto, Yoshida, A. Turner, J. L. A remarkable absorption feature at 28.5 keV, attributable to electron cyclotron resonance,...
view Abstract Citations (110) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Detections of Hard X-Ray Emissions from Bright Early-Type Galaxies with ASCA Matsushita, K. ; Makishima, Awaki, H. Canizares, C. R. Fabian, A. Fukazawa, Y. Loewenstein, M. Matsumoto, Mihara, T. Mushotzky, F. Ohashi, Ricker, G. Serlemitsos, P. J. Tsuru, Tsusaka, Yamazaki, Five bright elliptical galaxies in the Virgo Cluster, NGC 4365, 4374 (M84), 4406 (M86), 4472...
The present paper reports on the RXTE observations of binary X-ray pulsar 4U0115+63, covering an outburst in 1999 March-April with 44 pointings. 3-30 keV PCA spectra and 15-50 HEXTE were analyzed jointly for cyclotron resonance features. When 3-50 luminosity at assumed distance 7 kpc was range (5-13)x10^{37} erg s^{-1}, harmonic double features observed absorption ~11 ~22 keV, as measured previously during typical outbursts. As decreased below \~5x10^{37} second disappeared, fundamental...
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...
We report the results from X-ray studies of newly discovered black hole candidate MAXI J1305-704 based on Suzaku and Swift observations in low/hard high/soft states, respectively. The long observation shows two types clear absorption dips, both which recur a dip interval 9.74 +- 0.04 hours, we identify with orbital period. There is also partially ionized non-dip (persistent) emission state and, very unusually, state. However, this (in states) has substantially lower ionization than that seen...
The archetypical very-high-energy γ-ray blazar Mrk 421 was monitored for more than three years with the Gas Slit Camera on board Monitor of All Sky X-ray Image (MAXI), and its long-term variability investigated. MAXI light curve in 3–10 keV range transformed into periodogram frequency f = 1 × 10−8–2 10−6 Hz. artifacts periodogram, resulting from data gaps observed curve, were extensively simulated variations a power-law-like power spectrum density (PSD). By comparing periodograms, PSD index...