59 citations · 276 across the 18 of their papers we have counts for
18 papers
Radiative Efficiency Enhancement by Electromagnetic Energy Dissipation in Strongly Magnetized Supercritical Accretion Flows around Kerr Black Holes
Hiroyuki R. Takahashi, Ken Ohsuga, Ryohei Kobayashi +4
We investigate how black hole spin and the amount of magnetic flux affect electromagnetic energy dissipation and radiation transport in supercritical accretion flows. For this purp…
An ALMA view of the Jet-Arc CO clouds toward the TeV -ray source HESS J1023-575 and Westerlund 2; Evidence for the footprints of microquasar jets, the very powerful cosmic-ray accelerator in the Galactic disk
Yasuo Fukui, Kisetsu Tsuge, Hidetoshi Sano +7
The TeV -ray source HESS J1023-575 (HESSJ 1023 hereafter) is one of the brightest H.E.S.S. sources near the young massive cluster Westerlund 2. HESS J1023 shows a remarkable pos…
Clumpy Outflows from Super-Eddington Accreting Black Holes I: Radiation Hydrodynamics Simulations and Observational Implications
Haojie Hu, Yuta Asahina, Shogo Yoshioka +2
Recent advances in X-ray spectroscopic observation have enabled researchers to reveal distinct clumpy structures in the super-Eddington outflows from the supermassive black hole in…
GR-RMHD Simulations of Super-Eddington Accretion Flows onto a Neutron Star with Dipole and Quadrupole Magnetic Fields
Akihiro Inoue, Ken Ohsuga, Hiroyuki R. Takahashi +2
Although ultraluminous X-ray pulsars (ULXPs) are believed to be powered by super-Eddington accretion onto a magnetized neutron star (NS), the detailed structures of the inflow-outf…
General Relativistic Radiation Magnetohydrodynamics Simulations of Precessing Tilted Super-Eddington Disks
Yuta Asahina, Ken Ohsuga
We perform a three-dimensional general relativistic radiation magnetohydrodynamics simulation of a tilted super-Eddington accretion disk around the spinning black hole (BH). The di…
A Relativistic Formula for the Multiple Scattering of Photons
Rohta Takahashi, Masayuki Umemura, Ken Ohsuga +6
We have discovered analytical expressions for the probability density function (PDF) of photons that are multiply scattered in relativistic flows, under the assumption of isotropic…
Modeling of Thermal Emission from ULX Pulsar Swift J0243.6+6124 with General Relativistic Radiation MHD simulations
Akihiro Inoue, Ken Ohsuga, Hiroyuki R. Takahashi +1
We perform general relativistic radiation magnetohydrodynamics (MHD) simulations of super-Eddington accretion flows around a neutron star with a dipole magnetic field for modeling…
3D Photon Conserving Code for Time-dependent General Relativistic Radiative Transfer : CARTOON
Mikiya M. Takahashi, Ken Ohsuga, Rohta Takahashi +3
We develop the 3-dimensional general relativistic radiative transfer code: CARTOON (Calculation code of Authentic Radiative Transfer based On phOton Number conservation in curved s…
Component of energy flow from supercritical accretion disks around rotating stellar mass black holes
Aoto Utsumi, Ken Ohsuga, Hiroyuki R. Takahashi +1
By performing two-dimensional axisymmetric general relativistic radiation magnetohydrodynamics simulations with spin parameter varying from -0.9 to 0.9, we investigate the de…
Magnetic support for neutrino-driven explosion of 3D non-rotating core-collapse supernova models
Jin Matsumoto, Yuta Asahina, Tomoya Takiwaki +2
The impact of the magnetic field on postbounce supernova dynamics of non-rotating stellar cores is studied by performing three-dimensional magnetohydrodynamics simulations with spe…
Two-dimensional numerical study for magnetic field dependence of neutrino-driven core-collapse supernova models
Jin Matsumoto, Tomoya Takiwaki, Kei Kotake +2
We study the effects of the magnetic field on the dynamics of non-rotating stellar cores by performing two-dimensional (2D), magnetohydrodynamics (MHD) simulations. To this end, we…
Magnetohydrodynamic Simulations of a Plunging Black Hole into a Molecular Cloud
Mariko Nomura, Tomoharu Oka, Masaya Yamada +4
Using two-dimensional magnetohydrodynamic simulations, we investigated the gas dynamics around a black hole plunging into a molecular cloud. In these calculations, we assumed a par…
Three-dimensional structure of clumpy outflow from supercritical accretion flow onto black holes
Hiroshi Kobayashi, Ken Ohsuga, Hiroyuki R. Takahashi +4
We perform global three-dimensional (3D) radiation-hydrodynamic (RHD) simulations of out- flow from supercritical accretion flow around a 10 Msun black hole. We only solve the outf…
Magnetohydrodynamic Simulations of the Formation of Molecular Clouds toward the Stellar Cluster Westerlund 2: Interaction of a Jet with Clumpy Interstellar Medium
Yuta Asahina, Tomohisa Kawashima, Naoko Furukawa +4
The formation mechanism of CO clouds observed with NANTEN2 and Mopra telescope toward the stellar cluster Westerlund 2 is studied by three-dimensional magnetohydrodynamic (MHD) sim…
Magnetohydrodynamic Simulation Code CANS+: Assessments and Applications
Yosuke Matsumoto, Yuta Asahina, Yuki Kudoh +7
We present a new magnetohydrodynamic (MHD) simulation code with the aim of providing accurate numerical solutions to astrophysical phenomena where discontinuities, shock waves, and…
Magneto-hydrodynamic Simulations of a Jet Drilling an HI Cloud: Shock Induced Formation of Molecular Clouds and Jet Breakup
Y. Asahina, T. Ogawa, T. Kawashima +5
The formation mechanism of the jet-aligned CO clouds found by NANTEN CO observations is studied by magnetohydrodynamical (MHD) simulations taking into account the cooling of the in…
The jet and arc molecular clouds toward Westerlund 2, RCW 49, and HESS J1023-575; 12CO and 13CO (J=2-1 and J=1-0) observations with NANTEN2 and Mopra Telescope
N. Furukawa, A. Ohama, T. Fukuda +20
We have made new CO observations of two molecular clouds, which we call "jet" and "arc" clouds, toward the stellar cluster Westerlund 2 and the TeV gamma-ray source HESS J1023-575.…
Discovery of possible molecular counterparts to the infrared Double Helix Nebula in the Galactic center
R. Enokiya, K. Torii, M. Schultheis +23
We have discovered two molecular features at radial velocities of -35 km/s and 0 km/s toward the infrared Double Helix Nebula (DHN) in the Galactic center with NANTEN2. The two fea…