252 citations · 2k across the 48 of their papers we have counts for
47 papers
J-GEM near-infrared follow-up observations of the gravitational wave event S240422ed
Ichiro Takahashi, Tomoki Morokuma, Masaomi Tanaka +9
We report our near-infrared (NIR) follow-up observations of the gravitational wave (GW) event S240422ed using the Subaru Telescope/MOIRCS. S240422ed was initially classified as a b…
Neutrino pair annihilation driven jets from black-hole torus systems
Kyohei Kawaguchi, Sho Fujibayashi, Masaru Shibata
We perform axisymmetric general relativistic radiation-viscous hydrodynamics simulations of black hole (BH)-torus systems with full Boltzmann Monte-Carlo neutrino transport to inve…
Signatures of Exploding Supermassive PopIII Stars at High Redshift in JWST, EUCLID and Roman Space Telescope
Cédric Jockel, Kyohei Kawaguchi, Sho Fujibayashi +1
Recently discovered supermassive black holes with masses of at redshifts - in active galactic nuclei (AGN) pose severe challenges to our understandi…
Black hole-accretion disk collision in general relativity: Axisymmetric simulations
Alan Tsz-Lok Lam, Masaru Shibata, Kyohei Kawaguchi +1
Motivated by recent discoveries of X-ray quasi-periodic eruptions, we revisit the collision of a black hole and an accretion disk. Assuming that they are orbiting a supermassive bl…
Collapse of Rotating White Dwarfs and Multimessenger Signals
Takami Kuroda, Kyohei Kawaguchi, Masaru Shibata
We present results of numerical relativity simulations for the collapse of rotating magnetized white dwarfs (WDs) in three dimension, aiming at discussing the explosion dynamics an…
Viscous accretion and ejection from tori around black holes in general relativity
Masaru Shibata, Kyohei Kawaguchi, Alan Tsz-Lok Lam
We systematically perform long-term (millions of Schwarzschild time) axisymmetric viscous hydrodynamics simulations for tori around black holes in general relativity supposing the…
Linking Analytic Light Curve Models to Physical Properties of Kilonovae
Ayari Kitamura, Kyohei Kawaguchi, Masaomi Tanaka +1
In binary neutron star mergers, lanthanide-rich dynamical ejecta and lanthanide-poor post-merger ejecta have been often linked to the red and blue kilonova emission, respectively.…
Long-term Monte Carlo-based neutrino-radiation hydrodynamics simulations for a black hole-torus system
Kyohei Kawaguchi, Sho Fujibayashi, Masaru Shibata
We present our new general relativistic Monte Carlo (MC)-based neutrino radiation hydrodynamics code designed to solve axisymmetric systems with several improvements. The main impr…
Threshold mass of the general relativistic instability for supermassive star cores
Masaru Shibata, Sho Fujibayashi, Cédric Jockel +1
The dependence of the final fate of supermassive star (SMS) cores on their mass and angular momentum is studied with simple modeling. SMS cores in the hydrogen burning phase encoun…
Powerful explosions from the collapse of rotating supermassive stars
Sho Fujibayashi, Cédric Jockel, Kyohei Kawaguchi +2
We perform new general relativistic hydrodynamics simulations for collapses of rotating supermassive star cores with an approximate nuclear burning up to carbon and a detailed equa…
GRB 211211A: The Case for an Engine Powered over r-Process Powered Blue Kilonova
Hamid Hamidani, Masaomi Tanaka, Shigeo S. Kimura +2
The recent Gamma-Ray Burst (GRB) GRB 211211A provides the earliest ( h) data of a kilonova (KN) event, displaying bright ( erg s) and blue early emissio…
Black hole-neutron star mergers with massive neutron stars in numerical relativity
Shichuan Chen, Luohan Wang, Kota Hayashi +3
We study the merger of black hole-neutron star (BH-NS) binaries in numerical relativity, focusing on the properties of the remnant disk and the ejecta, varying the mass of compactn…
Three dimensional end-to-end simulation for kilonova emission from a black-hole neutron-star merger
Kyohei Kawaguchi, Nanae Domoto, Sho Fujibayashi +5
We study long-term evolution of the matter ejected in a black-hole neutron-star (BH-NS) merger employing the results of a long-term numerical-relativity simulation and nucleosynthe…
XKN: a Semi-analytic Framework for the Modelling of Kilonovae
Giacomo Ricigliano, Albino Perego, Ssohrab Borhanian +4
After GW170817, kilonovae have become of great interest for the astronomical, astrophysics and nuclear physics communities, due to their potential in revealing key information on t…
Kilonovae of binary neutron star mergers leading to short-lived remnant neutron star formation
Kyohei Kawaguchi, Sho Fujibayashi, Nanae Domoto +3
We study kilonova emission from binary neutron star (BNS) mergers for the case that a remnant massive neutron star (MNS) forms and collapses to a black hole within ms after th…
Cerium features in kilonova near-infrared spectra: implication from a chemically peculiar star
Masaomi Tanaka, Nanae Domoto, Wako Aoki +14
Observations of the kilonova from a neutron star merger event GW170817 opened a way to directly study r-process nucleosynthesis by neutron star mergers. It is, however, challenging…
A Monte-Carlo based relativistic radiation hydrodynamics code with a higher-order scheme
Kyohei Kawaguchi, Sho Fujibayashi, Masaru Shibata
We develop a new relativistic radiation hydrodynamics code based on the Monte-Carlo algorithm. In this code, we implement a new scheme to achieve the second-order accuracy in time…
Lanthanide Features in Near-infrared Spectra of Kilonovae
Nanae Domoto, Masaomi Tanaka, Daiji Kato +3
The observations of GW170817/AT2017gfo have provided us with evidence that binary neutron star mergers are sites of -process nucleosynthesis. However, the observed signatures in…
Opacity of the highly ionized lanthanides and the effect on the early kilonova
Smaranika Banerjee, Masaomi Tanaka, Daiji Kato +3
We investigate the effect of the presence of lanthanides (Z = 57- 71) on the kilonova at t~hours after the neutron star merger for the first time. For this purpose, we calculate th…
Electromagnetic counterparts of binary neutron star mergers leading to a strongly magnetized long-lived remnant neutron star
Kyohei Kawaguchi, Sho Fujibayashi, Kenta Hotokezaka +2
We explore the electromagnetic counterparts that will associate with binary neutron star mergers for the case that remnant massive neutron stars survive for s after…
Investigating GW190425 with numerical-relativity simulations
Reetika Dudi, Ananya Adhikari, Bernd Brügmann +7
The third observing run of the LIGO-Virgo collaboration has resulted in about hundred gravitational-wave triggers including the binary neutron star merger GW190425. However, none o…
Gravitational Wave Physics and Astronomy in the nascent era
Makoto Arimoto, Hideki Asada, Michael L. Cherry +50
The detections of gravitational waves (GW) by LIGO/Virgo collaborations provide various possibilities to physics and astronomy. We are quite sure that GW observations will develop…
Signatures of r-process elements in kilonova spectra
Nanae Domoto, Masaomi Tanaka, Shinya Wanajo +1
Binary neutron star (NS) mergers have been expected to synthesize r-process elements and emit radioactively powered radiation, called kilonova. Although r-process nucleosynthesis w…
A low-mass binary neutron star: long-term ejecta evolution and kilonovae with weak blue emission
Kyohei Kawaguchi, Sho Fujibayashi, Masaru Shibata +2
We study the long-term evolution of ejecta formed in a binary neutron star (BNS) merger that results in a long-lived remnant NS by performing a hydrodynamics simulation with the ou…