A5077592986- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Neutrino Physics Research
- Superconducting and THz Device Technology
- Black Holes and Theoretical Physics
- High-pressure geophysics and materials
- Cosmology and Gravitation Theories
- Planetary Science and Exploration
- Radiation Detection and Scintillator Technologies
- Laser-Plasma Interactions and Diagnostics
The University of Tokyo
2021-2025
Bunkyo University
2024
Kavli Institute for the Physics and Mathematics of the Universe
2021
Tohoku University
2021
Princeton University
2018-2020
Mergers of binary neutron stars and black hole-neutron star binaries are one the most promising sources for ground-based gravitational-wave (GW) detectors also a high-energy astrophysical phenomenon as illustrated by observations gravitational waves electromagnetic (EM) in event GW170817. these neutron-star site r-process nucleosynthesis. Numerical simulation full general relativity (numerical relativity) is unique approach to theoretical prediction merger process, GWs emitted, mass ejection...
The cores of neutron stars (NSs) near the maximum mass can realize a transitional change to quark matter (QM). Gravitational waves from binary NS mergers are expected convey information about equation state (EOS) sensitive QM transition. Here, we present first results gravitational wave simulation with realistic EOS that is consistent ab initio approaches χEFT and pQCD assumed go through smooth crossover. We compare them obtained another first-order hadron-quark phase Our suggest early...
We constrain the formation rate of Galactic magnetars directly from observations. Combining spin-down rates, magnetic activity, and association with supernova remnants, we put a 2$\sigma$ limit on their at $2.3-20\mbox{kyr}^{-1}$. This leads to fraction $0.4_{-0.28}^{+0.6}$ neutron stars being born as magnetars. study evolutionary channels that can account for this well periods, period derivatives luminosities observed population. find typical fields birth are $3\times 10^{14}-10^{15}$G,...
Joint multi-messenger observations with gravitational waves and electromagnetic data offer new insights into the astrophysical studies of compact objects. The third Advanced LIGO Virgo observing run began on April 1, 2019; during eleven months observation, there have been 14 binary systems candidates for which at least one component is potentially a neutron star. Although intensive follow-up campaigns involving tens ground space-based observatories searched counterparts, no counterpart has...
The nebular phase of lanthanide-rich ejecta a neutron star merger (NSM) is studied by using one-zone model, in which the atomic properties are represented single species, neodymium (Nd). Under assumption that beta-decay r-process nuclei heat and ionization source, we solve thermal balance under non-local thermodynamic equilibrium. data including energy levels, radiative transition rates, collision strengths, recombination rate coefficients, obtained structure codes, GRASP2K HULLAC. We find...
Extensions to general relativity allow the polarization of gravitational waves (GW) from astrophysical sources suffer amplitude and velocity birefringence, which respectively induce changes in ellipticity orientation tensor. We introduce a multimessenger approach test this behavior GWs during their cosmological propagation using binary sources, for initial is determined by inclination angles orbital angular momentum vector with respect line sight. In particular, we use spatially resolved...
A core collapse supernova occurs when exothermic fusion ceases in the of a massive star, which is typically caused by exhaustion nuclear fuel. Theory predicts that could be interrupted earlier merging star with compact binary companion. We report luminous radio transient, VT J121001+495647, found Very Large Array Sky Survey. The emission consistent ejecta colliding dense shell material, potentially ejected interaction centuries before explosion. associate an archival x-ray implies...
Abstract GW170817 is the first binary neutron star merger detected with gravitational and electromagnetic waves, its afterglow still detectable 7 years post-merger. Some previous studies of X-ray have claimed onset a new component or raised concerns about data processing techniques. Motivated thus, we present here reanalysis for find potential sources discrepancies between reduction techniques employed by various research groups. We also analyze updated panchromatic to that there no...
We develop stellar population models to predict the number of binaries with a single luminous member is Gaia and Hipparcos. Our yield dozens detections black hole - companion (BHLC) hundreds thousands neutron star (NSLC) Gaia. Interestingly, our also detection BHLC binary Hipparcos, few NSLC binaries. show how statistical distribution detected can be used constrain formation process stars holes.
Elementary particles such as quarks and gluons are expected to be fundamental degrees of freedom at ultra high temperatures or densities, while natural phenomena in our daily lives described terms hadronic freedom. Massive neutron stars remnants binary star mergers may contain quark matter, but it is not known how the transition from hadron matter occurs. Different scenarios predict different gravitational waveforms emitted mergers. If difference between equations state occurs sufficiently...
Abstract The detection of gravitational waves from the binary neuron star merger GW170817 and electromagnetic counterparts GRB170817A AT2017gfo kick-started field gravitational-wave multimessenger astronomy. optically red to near-infrared emission (“red” component) was readily explained as produced by decay newly created nuclei rapid neutron capture (a kilonova). However, ultraviolet blue (“blue” that dominant at early times (up 1.5 days) received no consensus regarding its driving physics....
We present a comprehensive study of neutrino shock acceleration in core-collapse supernova (CCSN). The leading players are heavy leptonic neutrinos, $\nu_{\mu}$ and $\nu_{\tau}$; the former latter potentially gain energy up to $\sim 100$ MeV 200$ MeV, respectively, through acceleration. Demonstrating by Monte Carlo transport, we make statement that it commonly occurs early post bounce phase ($\lesssim 50$ ms after bounce) for all massive stellar collapse experiencing nuclear would reoccur...
Abstract We discuss prospects of identifying and characterizing black hole (BH) companions to normal stars on tight but detached orbits, using photometric data from the Transiting Exoplanet Survey Satellite ( TESS ). focus following two periodic signals visible stellar component: (i) in-eclipse brightening star due gravitational microlensing by BH (self-lensing), (ii) a combination ellipsoidal variations tidal distortion relativistic beaming its orbital motion (phase-curve variation)....
A core-collapse supernova occurs when exothermic fusion ceases in the core of a massive star, typically due to exhaustion nuclear fuel. Theory predicts that could be interrupted earlier, by merging star with compact binary companion. We report luminous radio transient, VT J121001+495647, found Very Large Array Sky Survey. The emission is consistent ejecta colliding dense shell material, potentially ejected interaction centuries prior explosion. associate an archival X-ray which implies...