A5083131983- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Nuclear physics research studies
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- High-Energy Particle Collisions Research
- Particle accelerators and beam dynamics
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Astronomical and nuclear sciences
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Space Satellite Systems and Control
- Nuclear Physics and Applications
- Astronomy and Astrophysical Research
- Magnetic confinement fusion research
- Atmospheric Ozone and Climate
- Laser-Plasma Interactions and Diagnostics
National Astronomical Observatory of Japan
2014-2025
Waseda University
2008-2024
Tokyo University of Science
2022-2024
Japan Aerospace Exploration Agency
2024
Institute of Space and Astronautical Science
2024
Yamagata University
2024
Princeton University
2018-2022
University of California, Berkeley
2021-2022
Rikkyo University
2018-2020
California Institute of Technology
2016-2019
We have conducted nineteen state-of-the-art 3D core-collapse supernova simulations spanning a broad range of progenitor masses. This is the largest collection sophisticated ever performed. found that while majority these models explode, not all do, and even in middle available mass may be less explodable. does mean those for which we did witness explosion would explode Nature, but they are prone to than others. One consequence "compactness" measure metric explodability. find lower-mass...
We study the gravitational wave signal from eight new 3D core-collapse supernova simulations. show that is dominated by $f$- and $g$-mode oscillations of protoneutron star its frequency evolution encodes contraction rate latter, which, in turn, known to depend on star's mass, equation state, transport properties warm nuclear matter. A lower-frequency component signal, associated with standing accretion shock instability, found only one our models. Finally, we energy radiated waves...
One of the greatest uncertainties in any modeling inner engine core-collapse supernova (CCSN) is neutrino flavor conversions driven by self-interactions. We carry out large-scale numerical simulations multi-energy, multi-angle, three-flavor framework, and general relativistic quantum kinetic transport spherical symmetry with an essential set neutrino-matter interactions under a realistic fluid profile CCSN. Our result suggests that heating gain region reduced $\sim 40\%$ due to fast...
We present a comprehensive study on the occurrences of collisional flavor instability (CFI) and fast (FFI) neutrinos based 2D core-collapse supernova simulation performed with Boltzmann radiation hydrodynamics code. find that CFI occurs in region baryon-mass density ${10}^{10}\ensuremath{\lesssim}\ensuremath{\rho}\ensuremath{\lesssim}{10}^{12}\text{ }\text{ }\mathrm{g}\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$, which is similar to previous results 1D models. In contrast 1D, however, varies...
The observations of jet breaks in the afterglows short gamma-ray bursts (SGRBs) indicate that has a small opening angle < 10°. collimation mechanism is longstanding theoretical problem. We numerically analyze propagation material ejected by double neutron star merger, and demonstrate if ejecta mass > 10^{-2} M_{sun}, well confined cocoon emerges from with required angle. Our results also suggest there are some populations choked (failed) SGRBs or low-luminous new types event. By...
Recent theoretical work indicates that the neutrino radiation in core-collapse supernovae may be susceptible to flavor instabilities set far behind shock, grow extremely rapidly, and have potential profoundly affect supernova dynamics composition. Here we analyze nonlinear collective oscillations are prefigured by these instabilities. We demonstrate a zero crossing ${n}_{{\ensuremath{\nu}}_{e}}\ensuremath{-}{n}_{{\overline{\ensuremath{\nu}}}_{e}}$ as function of propagation angle is not...
We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at RIKEN Radioactive Isotope Beam Factory by using time-of-flight magnetic-rigidity technique. The atomic excesses ^{55-57}Ca are determined for time to be -18650(160), -13510(250), and -7370(990) keV, respectively. examine emergence magicity N=34 based on new masses. masses provide experimental evidence appearance a sizable energy gap between 2p_{1/2} 1f_{5/2} orbitals in ^{54}Ca,...
We present the first results of our spatially axisymmetric core-collapse supernova simulations with full Boltzmann neutrino transport, which amount to a time-dependent 5-dimensional (2 in space and 3 momentum space) problem fact. Special relativistic effects are fully taken into account two-energy-grid technique. performed two for progenitor 11.2M, employing different nuclear equations-of-state (EOS's): Lattimer Swesty's EOS incompressibility K = 220MeV (LS EOS) Furusawa's based on mean...
Neutrinos are believed to have a key role in the explosion mechanism of core-collapse supernovae as they carry most energy released by gravitational collapse massive star. If their flavor is converted fast inside neutrino sphere, supernova may be influenced. This paper reporting results extended work our previous paper. We perform thorough survey electron lepton number (ELN) crossing one self-consistent, realistic Boltzmann simulations two spatial dimensions under axisymmetry for existence...
This paper proposes a new possibility of the collective neutrino oscillation in core-collapse supernovae. Neutrinos scattered on nuclei pre-shock region induce fast flavor instability outward direction and may have some observational consequences for supernovae neutrinos.
Abstract We present a linear stability analysis of the fast-pairwise neutrino flavor conversion based on result our latest axisymmetric core-collapse supernova (CCSN) simulation with full Boltzmann transport. In CCSN simulation, coherent asymmetric emissions electron-type neutrinos ( ν e ) and their antiparticles <?CDATA ${\bar{\nu }}_{{\rm{e}}}$?> ), in which asymmetries are anticorrelated each other, occur at almost same time as onset aspherical shock expansion. find that play crucial role...
Neutrinos are densely populated deep inside the core of massive stars after their gravitational collapse to produce supernova explosions and form compact such as neutron (NS) black holes (BH). It has been considered that they may change flavor identities through so-called fast-pairwise conversions induced by mutual forward scatterings. If is really case, dynamics explosion will be influenced, since conversion occur near neutrino sphere, from which neutrinos effectively emitted. In this...
Fast-pairwise collective neutrino oscillation represents a key uncertainty in the theory of core-collapse supernova (CCSN). Despite potentially significant impact on CCSN dynamics, it is usually neglected numerical models because formidable technical difficulties self-consistently incorporating this physics. In paper, we investigate prospects for occurrence fast flavor conversion by diagnosing electron lepton number (ELN) crossing more than dozen state-of-the-art three-dimensional models....
This paper presents the first systematic study of proto-neutron star (PNS) convection in three dimensions (3D) based on our latest numerical Fornax models core-collapse supernova (CCSN). We confirm that PNS commonly occurs, and then quantify basic physical characteristics convection. By virtue large number long-term models, diversity convective behavior emerges. find vigor is not correlated with CCSN dynamics at radii, but rather mass $-$ heavier masses are associated stronger boosts...
Mounting evidence indicates that neutrinos likely undergo fast flavor conversion (FFC) in at least some core-collapse supernovae. Outcomes of FFC, however, remain highly uncertain. Here we study the cascade flavor-field power from large angular scales momentum space down to small ones, showing FFC enhances this process and thereby hastens relaxation. Cascade also poses a computational challenge, which is present even if field stable: When reaches smallest scale calculation, error truncating...
Despite the theoretical indication that fast neutrino-flavor conversion (FFC) ubiquitously occurs iin core-collapse supernovae and binary neutron star mergers, lack of global simulations has been greatest obstacle to study their astrophysical consequences. In this Letter, we present large-scale (50 km) FFC in spherical symmetry by using a novel approach. We effectively rescale oscillation scale reducing number injected neutrinos simulation box, then extrapolate back case target density with...
There is mounting evidence that neutrinos undergo fast flavor conversion (FFC) in core-collapse supernova (CCSN). In this letter, we investigate the roles of stellar rotation on occurrence FFC by carrying out axisymmetric CCSN simulations with full Boltzmann neutrino transport. Our result suggests electron lepton number (ELN) angular crossings, which are necessary and sufficient condition to trigger FFC, preferably occur equatorial region for rotating CCSNe. By scrutinizing neutrino--matter...
Neutrino-neutrino forward scatterings potentially induce collective neutrino oscillation in dense gases astrophysical sites such as core-collapse supernovae (CCSNe) and binary neutron star mergers (BNSMs). In this paper, we present a detailed study of fast neutrino-flavor conversion (FFC), paying special attention to asymptotic states, by means stability analysis local simulations with periodic boundary condition. We find that states can be characterized two key properties FFC: (1) the...
The question of what ingredients characterize the quasi-steady state fast neutrino-flavor conversion (FFC) is one long-standing riddles in neutrino oscillation. Addressing this issue necessary for accurate modeling transport core-collapse supernova and binary neutron star merger. Recent numerical simulations FFC have shown, however, that sensitively dependent on boundary conditions space, physical reason dependence not clear at present. In study, we provide a interpretation based arguments...
We present a systematic study of fast neutrino-flavor conversion (FFC) with both small-scale and large-scale numerical simulations in spherical symmetry. find that FFCs can, general, reach quasi-steady state, these features the non-linear phase are not characterized by growth rate FFC instability but rather angular structures electron neutrino lepton number (ELN) heavy one (XLN). Our result suggests neutrinos can almost flavor equipartition even cases low (e.g., shallow ELN crossing) narrow...
One of the active debates in core-collapse supernova (CCSN) theory is how significantly neutrino flavor conversions induced by neutrino-neutrino self-interactions change conventional picture CCSN dynamics. Recent studies have indicated that strong can occur inside spheres where neutrinos are tightly coupled to matter. These associated with either collisional instability or fast neutrino-flavor conversion (FFC) both. The impact these on dynamics is, however, still highly uncertain due lack...
We present a new subgrid model for neutrino quantum kinetics, which is primarily designed to incorporate effects of collective oscillations into neutrino-radiation-hydrodynamic simulations core-collapse supernovae and mergers compact objects. approximate the oscillation term in kinetic equation using Bhatnagar-Gross-Krook (BGK) relaxation-time prescription, transport directly applicable classical schemes. The BGK motivated by recent theoretical indications that nonlinear phases settle...
Neutrinos in dense environments like core-collapse supernovae (CCSNe) and neutron star mergers (NSMs) can undergo fast flavor conversions (FFCs) once the angular distribution of neutrino lepton number crosses zero along a certain direction. Recent advancements have demonstrated effectiveness machine learning (ML) detecting these crossings. In this study, we enhance prior research two significant ways. First, utilize realistic data from CCSN simulations, where transport is solved using full...
The sensitivity of current and future neutrino detectors like Super-Kamiokande (SK), JUNO, Hyper-Kamiokande (HK), DUNE is expected to allow for the detection diffuse supernova background (DSNB). However, DSNB model ingredients core-collapse (CCSN) rate, emission spectra, fraction failed supernovae are not precisely known. We quantify uncertainty on each these by (i) compiling a large database recent star formation rate density measurements, (ii) combining from long-term axisymmetric CCSNe...
We investigate by two-dimensional axisymmetric relativistic hydrodynamical simulations (1) jet propagations through an envelope of a rapidly rotating and collapsing massive star, which is supposed to be progenitor long duration gamma ray bursts (GRBs), (2) breakouts subsequent expansions into stellar winds (3) accompanying photospheric emissions.We find that if the rotates uniformly almost at mass shedding limit, its outer part stops contracting eventually when centrifugal force becomes...