A5036767884- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Laser Design and Applications
- Laser-Plasma Interactions and Diagnostics
- Stellar, planetary, and galactic studies
- Solid State Laser Technologies
- Laser-induced spectroscopy and plasma
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Photorefractive and Nonlinear Optics
- Spectroscopy and Laser Applications
- Astronomy and Astrophysical Research
- Laser Material Processing Techniques
- Neutrino Physics Research
- Advanced Fiber Laser Technologies
- Laser-Matter Interactions and Applications
- Dark Matter and Cosmic Phenomena
- Atomic and Molecular Physics
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Semiconductor Lasers and Optical Devices
Kagoshima University
2023-2025
Kyoto University
2013-2024
Okayama University
2019-2023
Hiroshima University
2010-2023
Obayashi (Japan)
2001-2019
Geospatial Information Authority of Japan
2011-2018
Konan University
2014-2018
Osaka Kyoiku University
2006-2014
Osaka University
1992-2005
Institute for Laser Technology
1985-1992
A series of experiments focused on high neutron yield has been performed with the Gekko-XII green laser system [Nucl. Fusion 27, 19 (1987)]. Deuterium–tritium (DT) 1013 and pellet gain 0.2% have achieved. Based experimental data from more than 70 irradiations, scaling laws related physical quantities studied. Comparison that obtained by using a one-dimensional fluid code led to conclusion most neutrons produced in stagnation phase computation are not observed experiment because fuel–pusher...
We present time-resolved broad-band observations of the quasar 3C 279 obtained from multi-wavelength campaigns conducted during first two years Fermi Gamma-ray Space Telescope mission. While investigating previously reported gamma-ray/optical flare accompanied by a change in optical polarization, we found that emission appears delayed with respect to gamma-ray about 10 days. X-ray reveal pair `isolated' flares separated ~90 days, only weak counterparts. The spectral structure measured...
In this paper, we present the results from spectroscopic and photometric observations of M-type flare star YZ CMi in framework Optical Infrared Synergetic Telescopes for Education Research (OISTER) collaborations during Transiting Exoplanet Survey Satellite (TESS) observation period. We detected 145 white-light flares TESS light curve 4 H$\alpha$ OISTER performed between 2019-01-16 2019-01-18. Among them, 3 were associated with flares. However, one them did not show clear brightening...
Abstract We present early-stage analyses of low-resolution (R = 1000) optical spectra and near-infrared light curves the bright Type II supernova (SN II) 2023ixf in notable nearby face-on spiral galaxy M 101, which were obtained from t 1.7 to 8.0 d. Our first spectrum showed remarkable emission features Balmer series, He ii, N iii, C iv, iv with a strong blue continuum. Compared SNe show flash-ionized features, we suggest that this SN could be categorized as high-luminosity...
Direct-drive implosion experiments on the GEKKO XII laser (9 kJ, 0.5 μm, 2 ns) with deuterium and tritium (DT) exchanged plastic hollow shell targets demonstrated fuel areal densities (ρR) of ˜0.1 g/cm ˜600 times liquid density at temperatures ˜0.3 keV. (The ρR values refer only to DT do not include carbons in targets.) These are be compared thermonuclear ignition conditions, i.e., 500–1000 density, greater than 0.3 , 5 The irradiation nonuniformity these was significantly reduced a level...
We report on the correlation between flux, color and polarization variations time scales of days--months in blazars, discuss their universal aspects. performed monitoring 42 blazars optical near-infrared bands from 2008 to 2010 using TRISPEC attached "Kanata" 1.5-m telescope. found that 28 exhibited "bluer-when-brighter" trends whole or a part time-series data sets. This corresponds 88% objects were observed for >10 days. Thus, our observation unambiguously confirmed trend is common emission...
We report the late-time evolution of Type IIb supernova (SN IIb) 2013df. SN 2013df showed a dramatic change in its spectral features at ∼1 yr after explosion. Early on it typical characteristics shared by SNe IIb/Ib/Ic dominated metal emission lines, while later was broad and flat-topped Hα He i emissions. The spectra are strikingly similar to 1993J, which is only previous example clearly showing same transition. This fully explained energy input from 56Co decay interaction between ejecta...
We present an analysis of the nebular spectra 103 stripped envelope (SE) supernovae (SNe) collected from literature and observed with Subaru Telescope 2002 to 2012, focusing on [O I] 6300, 6363. The line profile width are employed infer ejecta geometry expansion velocity inner core. These two measurements then compared SN sub types, further I]/[Ca II] ratio, which is used as indicator progenitor CO core mass. Based best fit results profile, objects classified into different morphological...
Abstract We present a detailed investigation of photometric, spectroscopic, and polarimetric observations the Type II SN 2023ixf. Earlier studies have provided compelling evidence for delayed shock breakout from confined dense circumstellar matter (CSM) enveloping progenitor star. The temporal evolution polarization in 2023ixf phase revealed three distinct peaks at 1.4 days, 6.4 79.2 indicating an asymmetric CSM, aspherical front clumpiness low-density extended inner ejecta/He-core....
We present the first spectropolarimetric observations of a candidate super-Chandrasekhar mass Type Ia supernova (SN): SN 2009dc. The were performed at 5.6 and 89.5 days after B-band maximum. data taken later epoch are used to determine interstellar polarization. Continuum polarization is found be small (<0.3%), indicating that explosion nearly spherically symmetric. This fact suggests very aspherical not likely scenario for Polarization Si ii Ca lines clearly shows loop in Q–U plane,...
In this Letter we report a discovery of prominent flash peculiar overluminous Type Ia supernova, SN 2020hvf, in about 5 hours the supernova explosion by first wide-field mosaic CMOS sensor imager, Tomo-e Gozen Camera. The fast evolution early was captured intensive intranight observations via high-cadence survey. Numerical simulations show that such and emission is most likely generated from an interaction between $0.01~M_{\odot}$ circumstellar material (CSM) extending to distance...
ABSTRACT We present photometric, spectroscopic, and polarimetric observations of the intermediate-luminosity Type IIP supernova (SN) 2021gmj from 1 to 386 d after explosion. The peak absolute V-band magnitude SN is −15.5 mag, which fainter than that normal SNe. spectral evolution resembles other sub-luminous SNe: optical spectra show narrow P-Cygni profiles, indicating a low expansion velocity. estimate progenitor mass be about 12 $\rm {\rm M}_{\odot}$ nebular spectrum 56Ni 0.02 bolometric...
Some core-collapse supernovae (CCSNe) are too luminous and radiate much total energy to be powered by the release of thermal from ejecta radioactive-decay synthesised $^{56}$Ni/$^{56}$Co. A source additional power is interaction between supernova (SN) a massive circumstellar material (CSM). This an important in Type IIn SNe, which show narrow spectral lines arising unshocked CSM, but not all interacting SNe such lines. We present photometric spectroscopic observations hydrogen-rich SN...
Abstract We present the long-term photometric and spectroscopic analysis of a transitioning SN IIn/Ibn from −10.8 d to 150.7 post V-band maximum. 2021foa shows prominent He i lines comparable in strength Hα line around peak, placing between IIn Ibn populations. The spectral comparison that it resembles population at pre-maximum, becomes intermediate SNe post-maximum matches with 1996al. evolution precursor −50 light curve shoulder 17d. peak luminosity color are consistent most our sample....
We report the multi-band photometric observations of Type IIb supernova (SN) 2024iss with ultra-violet (UV), optical, and near-infrared (NIR) wavelengths starting one day after explosion. The UV optical light curves show first peak two days explosion date. Following a peak, secondary maximum is observed in NIR bands, similar to SNe double-peaked curves. quasi-bolometric curve shows fast decay until week From analysis bolometric curve, ejecta mass kinetic energy are estimated be...
Abstract We report the multi-band photometric observations of Type IIb supernova (SN) 2024iss at ultraviolet (UV), optical, and near-infrared (NIR) wavelengths starting one day after explosion. The UV optical light curves show first peak two days explosion date. Following peak, a secondary maximum is observed in NIR bands, similar to SNe with double-peaked curves. quasi-bolometric curve shows fast decay for week From analysis bolometric curve, ejecta mass kinetic energy are estimated be...
For prompt optical polarimetry of gamma-ray burst (GRB) afterglow, we require wide-field imaging polarimeter which can produce both Stokes <i>Q</i> and <i>U</i> parameters from only a single exposure, as well quickly-moving telescope enclosure system. HOWPol is an provides four linearly polarized images at position angles 0°, 45°, 90° 135°, i.e., <i>I</i>, <i>Q</i>, <i>U</i>, simultaneously. The key device the wedged double Wollaston prism described by Oliva...
The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio by Whole Earth Blazar Telescope (WEBT) collaboration organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra INTEGRAL in mid-January, additional coverage RXTE Swift XRT. In this paper we focus on results WEBT campaign. source exhibited substantial variability optical flux spectral shape, a characteristic timescale few days....
During the month of 2009 December, blazar 3C 454.3 became brightest gamma-ray source in sky, reaching a peak flux F ∼ 2000 × 10−8 photons cm−2 s−1 for E > 100 MeV. Starting November intensive multifrequency campaigns monitored 454 outburst. Here, we report on results two-month campaign involving AGILE, INTEGRAL, Swift/XRT, Swift/BAT, and Rossi XTE high-energy observations Swift/UVOT, KANATA, Goddard Robotic Telescope, REM near-IR/optical/UV data. GASP/WEBT provided radio additional optical...
We report observations of the Type Iax supernova (SN Iax) 2012Z at optical and near-infrared (NIR) wavelengths from immediately after explosion until ∼260 days maximum luminosity using Optical Infrared Synergetic Telescopes for Education Research Target-of-Opportunity program Subaru Telescope. found that NIR light curve evolutions color are similar to those SNe 2005hk 2008ha. The absolute magnitudes ( mag mag) rate decline (m15(B) very SN mag, m15(B) 1.6 mag), yet differ significantly 2008ha...
We present optical and near-infrared observations of a low-luminosity Type IIP supernova (SN) 2016bkv from the initial rising phase to plateau phase. Our show that end is extended $\gtrsim 140$ days since explosion, indicating this SN takes one longest time finish among SNe (SNe IIP), including (LL) IIP. The line velocities various ions at middle are as low 1,000--1,500 km s$^{-1}$, which lowest even LL These measurements imply ejecta mass in larger than well-studied 2003Z. In early phase,...
The first demonstration of a fuel density-radius product measurement using secondary nuclear fusion reactions is presented. This technique involves neutrons and protons generated by DT {T(d,n)α} D3He {3He(d,p)α} reactions, respectively, in pure deuterium fuel.
We present optical spectroscopic and photometric observations of supernova (SN) 2008D, associated with the luminous X-ray transient 080109, at >300 days after explosion (nebular phases). also give flux measurements emission lines from H ii region site SN, estimates local metallicity. The brightness SN nebular phases is consistent prediction models an ejected 56Ni mass 0.07 M☉, which explains light curve early phases. [O i] line in spectrum shows a double-peaked profile while [Ca ii] does...
Supernovae (SNe) have been proposed to be the main production sites of dust grains in Universe. Our knowledge on their importance is, however, limited by observationally poor constraints nature and amount particles produced individual SNe. In this paper, we present a spectrum covering optical through near-Infrared (NIR) light luminous Type IIn supernova (SN IIn) 2010jl around one half years after explosion. This unique data set reveals multiple signatures newly formed particles. The NIR...
We report that the optical polarization in afterglow of GRB 091208B is measured at t = 149–706 s after burst trigger, and degree P 10.4{ ± 2.5%. The light curve this time shows a power-law decay with index −0.75 0.02, which interpreted as forward shock synchrotron emission, thus first detection early-time (rather than reverse reported by Steele et al.). This disfavors model magnetic fields emission region are random on plasma skin depth scales, such those amplified instabilities, e.g.,...