A5043891525- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- SAS software applications and methods
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Astronomy and Astrophysical Research
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Nuclear Physics and Applications
- Statistical and numerical algorithms
- High-pressure geophysics and materials
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Astrophysics and Star Formation Studies
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- CCD and CMOS Imaging Sensors
- Radio Astronomy Observations and Technology
- Particle Accelerators and Free-Electron Lasers
- Planetary Science and Exploration
- Advanced X-ray Imaging Techniques
Tokyo Institute of Technology
2015-2024
Kanazawa University
2008-2024
RIKEN
2008-2023
Nippon Soken (Japan)
1996-2023
Saitama University
2020-2022
Fukuyama City Hospital
2022
Wayo Women's University
2022
National Astronomical Observatory of Japan
2005-2020
Centrum Badań Kosmicznych
2018
Polish Academy of Sciences
2018
The Transiting Exoplanet Survey Satellite (TESS) will search for planets transiting bright and nearby stars. TESS has been selected by NASA launch in 2017 as an Astrophysics Explorer mission. spacecraft be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with I = 4-13 temporary drops brightness caused planetary transits. Each star observed interval...
The Transiting Exoplanet Survey Satellite (TESS ) will search for planets transiting bright and nearby stars. TESS has been selected by NASA launch in 2017 as an Astrophysics Explorer mission. spacecraft be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with I<sub>C</sub> (approximately less than) 13 temporary drops brightness caused planetary...
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.
Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with large acceptance exceeding 2 m;{2} sr at 300 GeV. Building on analysis, we have developed efficient detection strategy which provides sufficient background rejection for measurement of steeply falling spectrum up to 1 TeV. Our high precision data show that falls energy E-3.0 and does not exhibit prominent spectral features. Interpretations in terms conventional diffusive...
We report on the first Fermi Large Area Telescope (LAT) measurements of so-called "extragalactic" diffuse gamma-ray emission (EGB). This component is generally considered to have an isotropic or nearly distribution sky with diverse contributions discussed in literature. The derivation EGB based detailed modeling bright foreground Galactic emission, detected LAT sources, and solar emission. find spectrum consistent a power law differential spectral index gamma = 2.41 +/- 0.05 intensity I(>100...
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 Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope ( ) began a sky survey August. The Large Area (LAT) on three months produced deeper and better resolved map of γ-ray than any previous space mission. We present here initial results for energies above 100 MeV 205 most significant (statistical significance greater ∼10σ) sources these data. These are best characterized localized point-like (i.e., spatially unresolved) early mission
We report on the observation of bright, long gamma-ray burst, GRB 090902B, by Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) instruments on-board Fermi observatory. This was one brightest GRBs to have been observed LAT, which detected several hundred photons during prompt phase. With a redshift z = 1.822, this burst is among most luminous Fermi. Time-resolved spectral analysis reveals significant power-law component in LAT data that distinct from usual Band model emission seen...
This paper presents light curves as well the first systematic characterization of variability 106 objects in high-confidence Fermi Large Area Telescope Bright AGN Sample (LBAS). Weekly this sample, obtained during 11 months survey (2008 August 4–2009 July 4), are tested for and their properties quantified through autocorrelation function structure analysis. For brightest sources, 3 or 4 day binned extracted order to determine power density spectra (PDSs) fit temporal major flares. More than...
Pulsars are rapidly-rotating, highly-magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there more than 1800 known radio pulsars, until recently, only seven were observed to pulse in gamma rays and these all discovered at other wavelengths. The Fermi Large Area Telescope makes it possible pinpoint through their gamma-ray pulsations. We report detection of 16 pulsars blind frequency searches using LAT. Most coincident with previously unidentified...
The first detected gravitational wave from a neutron star merger was GW170817. In this study, we present J-GEM follow-up observations of SSS17a, an electromagnetic counterpart SSS17a shows 2.5-mag decline in the $z$-band 1.7 days to 7.7 after merger. Such rapid is not comparable with supernovae light curves at any epoch. color also evolves rapidly and becomes redder for later epochs; $z-H$ changed by approximately 2.5 mag period 0.7 days. evolution both optical brightness are consistent...
Wide-field optical surveys have begun to uncover large samples of fast (trise ≲ 5 d), luminous (Mpeak < −18), blue transients. While commonly attributed the breakout a supernova shock into dense wind, great distances transients this class found so far hampered detailed investigation their properties. We present photometry and spectroscopy from comprehensive worldwide campaign observe AT 2018cow (ATLAS 18qqn), first fast-luminous transient be in real time at low redshift. Our spectra (<2 days...
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts long (>2 s) duration produced by the core-collapse massive stars, those short (< 2 merger two neutron stars (NSs). A third class events with hybrid properties was identified, but never conclusively linked to a stellar progenitor. The lack bright supernovae rules out typical explosions, their distance scales prevent sensitive searches for direct signatures progenitor system. Only...
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...
The gamma-ray burst (GRB) 050904 at z = 6.3 provides the first opportunity of probing intergalactic medium (IGM) by GRBs epoch reionization. Here we present a spectral modeling analysis optical afterglow spectrum taken Subaru Telescope, aiming to constrain reionization history. shows clear damping wing wavelengths redward Lyman break, and shape can be fit either damped Ly alpha system with column density log (N_HI/cm^{-2}) ~ 21.6 redshift close detected metal absorption lines (z_metal...
We report on gamma-ray observations of the Crab Pulsar and Nebula using 8 months survey data with Fermi Large Area Telescope (LAT). The high quality light curve obtained ephemeris provided by Nancay Jodrell Bank radio telescopes shows two main peaks stable in phase energy. first peak leads pulse (281 \pm 12 21) mus, giving new constraints production site non-thermal emission pulsar magnetospheres. improved sensitivity unprecedented statistics afforded LAT enable precise measurement spectral...
Recent observations of supernova remnants (SNRs) hint that they accelerate cosmic rays to energies close ~10(15) electron volts. However, the nature particles produce emission remains ambiguous. We report SNR W44 with Fermi Large Area Telescope at between 2 x 10(8) volts and 3 x10(11) The detection a source morphology corresponding shell implies is produced by accelerated there. gamma-ray spectrum well modeled from protons nuclei. Its steepening above approximately 10(9) provides probe which...
The discovery of bright gamma-ray emission coincident with supernova remnant (SNR) W51C is reported using the Large Area Telescope (LAT) on board Fermi Gamma-ray Space Telescope. a middle-aged (~10^4 yr) intense radio synchrotron in its shell and known to be interacting molecular cloud. spatially extended, broadly consistent X-ray extent SNR W51C. energy spectrum 0.2-50 GeV band exhibits steepening toward high energies. luminosity greater than 1x10^{36} erg/s given distance constraint D>5.5...