683 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Tohoku UniversityJP202 papers
- The University of TokyoJP78 papers
- Kyoto UniversityJP59 papers
- National Astronomical Observatory of JapanJP44 papers
- Kavli Institute for the Physics and Mathematics of the UniverseJP40 papers
- Nagoya UniversityJP33 papers
- The University of OsakaJP32 papers
- Massachusetts Institute of TechnologyUS30 papers
- Institute of Space and Astronautical ScienceJP27 papers
- Japan Aerospace Exploration AgencyJP26 papers
- Ehime UniversityJP24 papers
- Institute of Astronomy and Astrophysics, Academia SinicaTW24 papers
14 papers · 1 filter
Where is the electric current driven in the Blandford-Znajek process?
Kenji Toma, Fumio Takahara
The Blandford-Znajek process, the steady electromagnetic energy extraction from a rotating black hole, is widely believed to work for driving relativistic jets, although it is stil…
Rapid Black Hole Growth under Anisotropic Radiation Feedback
Kazuyuki Sugimura, Takashi Hosokawa, Hidenobu Yajima +1
Discovery of high-redshift (z > 6) supermassive black holes (BHs) may indicate that the rapid (or super-Eddington) gas accretion has aided their quick growth. Here, we study such r…
Detection of a hot molecular core in the Large Magellanic Cloud with ALMA
Takashi Shimonishi, Takashi Onaka, Akiko Kawamura +1
We report the first detection of a hot molecular core outside our Galaxy based on radio observations with ALMA toward a high-mass young stellar object (YSO) in a nearby low metalli…
X-ray and Optical Correlation of Type I Seyfert NGC 3516 Studied with Suzaku and Japanese Ground-Based Telescopes
Hirofumi Noda, Takeo Minezaki, Makoto Watanabe +23
From 2013 April to 2014 April, we performed an X-ray and optical simultaneous monitoring of the type 1.5 Seyfert galaxy NGC 3516. It employed Suzaku, and 5 Japanese ground-based te…
Causal production of the electromagnetic energy flux and role of the negative energies in Blandford-Znajek process
Kenji Toma, Fumio Takahara
Blandford-Znajek process, the steady electromagnetic energy extraction from a rotating black hole (BH), is widely believed to work for driving relativistic jets in active galactic…
Links between the shock instability in core-collapse supernovae and asymmetric accretions of envelopes
Kazuya Takahashi, Wakana Iwakami, Yu Yamamoto +1
The explosion mechanism of core-collapse supernovae has not been fully understood yet but multi-dimensional fluid instabilities such as standing accretion shock instability (SASI)…
From Birth to Death of Protoplanetary Disks: Modeling Their Formation, Evolution, and Dispersal
Shigeo S. Kimura, Masanobu Kunitomo, Sanemichi Z. Takahashi
Formation, evolution, and dispersal processes of protoplanetary disks are investigated and the disk lifetime is estimated. Gravitational collapse of a pre-stellar core forms both a…
Laser frequency locking with 46 GHz offset using an electro-optic modulator for magneto-optical trapping of francium atoms
K. Harada, T. Aoki, S. Ezure +21
We demonstrated a frequency offset locking between two laser sources using a waveguide-type electro-optic modulator (EOM) with 10th-order sidebands for magneto-optical trapping of…
Gamma-ray bursts and Population III stars
Kenji Toma, Sung-Chul Yoon, Volker Bromm
Gamma-ray bursts (GRBs) are ideal probes of the epoch of the first stars and galaxies. We review the recent theoretical understanding of the formation and evolution of the first (s…
Direct measurement of the optical trap-induced decoherence
Nobuyuki Matsumoto, Kentaro Komori, Sosuke Ito +2
Thermal decoherence is a major obstacle to the realization of quantum coherence for massive mechanical oscillators. Although optical trapping has been used to reduce the thermal de…
Stochastic Particle Acceleration in Turbulence Generated by the Magnetorotational Instability
Shigeo S. Kimura, Kenji Toma, Takeru K. Suzuki +1
We investigate stochastic particle acceleration in accretion flows. It is believed that the magnetorotational instability (MRI) generates turbulence inside accretion flows and that…
Turbulent Cosmic-Ray Reacceleration and the Curved Radio Spectrum of the Radio Relic in the Sausage Cluster
Yutaka Fujita, Hiroki Akamatsu, Shigeo S. Kimura
It has often been thought that the northern radio relic in the galaxy cluster CIZA J2242.8+5301 (the "Sausage" Cluster) is associated with cosmic ray (CR) electrons that are accele…
Higher order test of Lorentz invariance with an optical ring cavity
Yuta Michimura, Jake Guscott, Matthew Mewes +5
We have developed an apparatus to search for the higher-order Lorentz violation in photons by measuring the resonant frequency difference between two counterpropagating directions…
Revised Wavelength and Spectral Response Calibrations for AKARI Near-Infrared Grism Spectroscopy: Cryogenic Phase
S. Baba, T. Nakagawa, M. Shirahata +6
We perform revised spectral calibrations for the AKARI near-infrared grism to quantitatively correct for the effect of the wavelength-dependent refractive index. The near-infrared…