教員・研究者詳細 - 山本　常夏

論文 - 山本　常夏

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Coherent Radio Emission from the electron beam sudden appearance 査読あり

Krijn D. de Vries, Michael DuVernois, Masaki Fukushima, Romain Gaïor, Kael Hanson, Daisuke Ikeda, Yusuke Inome, Aya Ishihara, Takao Kuwabara, Keiichi Mase, John N. Matthews, Thomas Meures, Pavel Motloch, Izumi S. Ohta, Aongus O’Murchadha, Florian Partous, Matthew Relich, Hiroyuki Sagawa, Tatsunobu Shibata, Bokkyun Shin, Gordon Thomson, Shunsuke Ueyama, Nick van Eijndhoven, Tokonatsu Yamamoto, and Shigeru Yoshida

Physical Review D 98 ( 123020 ) 1 - 8 2018年3月

共著

DOI： 10.1103/PhysRevD.98.123020

A Technique for Estimating the Absolute Gain of a Photomultiplier Tube 査読あり

M.Takahashi, Y.Inome, S.Yoshii, A.Bamba, S.Gunji, D.Hadasch, M.Hayashida, H.Katagiri, Y.Konno, H.Kubo, J.Kushida, D.Nakajima, T.Nakamori, T.Nagayoshi, K.Nishijima, S.Nozaki, D.Mazin, S.Mashuda, T. Yamamoto, T.Yoshida

Nuclear Instruments and methods in physics research section A 894 ( 21 ) 1 - 7 2018年6月

単著

DOI： 10.1016/j.nima.2018.03.034

Measurement of microwave radiation from electron beam in the atmosphere 査読あり

I. S. Ohta, H. Akimune, M. Fukushima, D. Ikeda, Y. Inome, J.N. Matthews, S. Ogio, H. Sagawa, T. Sako, T. Shibata, T. Yamamoto

Nuclear Instruments and methods in physics research section A 810 44 - 50 2016年2月

共著

担当区分：筆頭著者

DOI： 10.1016/j.nima.2015.11.113

Propagation of Ultra-High-Energy Cosmic Ray Nuclei in Cosmic Magnetic Fields and Implications for Anisotropy Measurements 査読あり

Hajime Takami, Susumu Inoue, Tokonatsu Yamamoto

Astroparticle Physics 35 ( 12 ) 767 - 780 2012年7月

共著

Recent results from the Pierre Auger Observatory (PAO) indicate that the composition of ultra-high-energy cosmic rays (UHECRs) with energies above $10^{19}$ eV may be dominated by heavy nuclei. An important question is whether the distribution of arrival directions for such UHECR nuclei can exhibit observable anisotropy or positional correlations with their astrophysical source objects despite the expected strong deflections by intervening magnetic fields. For this purpose, we have simulated the propagation of UHECR nuclei including models for both the extragalactic magnetic field and the Galactic magnetic field. Assuming that only iron nuclei are injected steadily from sources with equal luminosity and spatially distributed according to the observed large scale structure in the local Universe, at the number of events published by the PAO so far, the arrival distribution of UHECRs would be consistent with no auto-correlation at 95% confidence if the mean number density of UHECR sources $n_s >~ 10^{-6}$ Mpc$^{-3}$, and consistent with no cross-correlation with sources within 95% errors for $n_s >~ 10^{-5}$ Mpc$^{-3}$. On the other hand, with 1000 events above $5.5 \times 10^{19}$ eV in the whole sky, next generation experiments can reveal auto-correlation with more than 99% probability even for $n_s <~ 10^{-3}$ Mpc$^{-3}$, and cross-correlation with sources with more than 99% probability for $n_s <~ 10^{-4}$ Mpc$^{-3}$. In addition, we find that the contribution of Centaurus A is required to reproduce the currently observed UHECR excess in the Centaurus region. Secondary protons generated by photodisintegration of primary heavy nuclei during propagation play a crucial role in all cases, and the resulting anisotropy at small angular scales should provide a strong hint of the source location if the maximum energies of the heavy nuclei are sufficiently high.

その他リンク： http://xxx.yukawa.kyoto-u.ac.jp/PS_cache/arxiv/pdf/1202/1202.2874v1.pdf

Prototyping hexagonal light concentrators using high-reflectance specular films for the Large-Sized Telescopes of the Cherenkov Telescope Array 査読あり

A. Okumura, T.V. Dang, S. Ono, S. Tanaka, M. Hayashida, J. Hinton, H. Katagiri, K. Noda, T. Yamamoto, T. Yoshida

Journal of Instrujmentation 12 ( P12008 ) 1 - 18 2017年11月

共著

DOI： 10.1088/1748-0221/12/12/P12008

Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1718.7-3946 査読あり

F. Aceror, T. Nakamori, T. Yamamoto et. al. (456 in all)

Astrophysical Journal 840 ( 74 ) 1 - 14 2017年3月

共著

DOI： 10.3847/1538-4357/aa6d67

Evaluation of novel PMTs of worldwide best parameters for the CTA project 査読あり

R. Mirzoyan, D. Muller, J. Hose, U. Menzel, D. Nakajima, M. Takahashi, M. Teshima, T. Toyama, T. Yamamoto

Nuclear Instruments and methods in physics research section A 845 603 - 606 2017年2月

共著

DOI： 10.1016/j.nima.2016.06.080

Evaluation of Photo Multiplier Tube candidates for the Cherenkov Telescope Array 査読あり

T. Toyama, Y. Hanabata, J. Hose, U. Menzel, R. Mirzoyan, D. Nakajima, M. Takahashi, M. Teshima, T. Yamamoto

Nuclear Instruments and methods in physics research section A 787 280 - 283 2015年8月

共著

DOI： 10.1016/j.nima.2015.08.030

Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC

MAGIC collaboration

Physical Review Letters 2023年2月

DOI： 10.1103/physrevlett.130.061002

Proton acceleration in thermonuclear nova explosions revealed by gamma rays

CTA consortumu

Nature Astronomy 2022年6月

DOI： 10.1038/s41550-022-01640-z

Multiwavelength Observations of the Blazar VER J0521+211 during an Elevated TeV Gamma-Ray State

CTA consortumu

The Astrophysical Journal 2022年6月

DOI： 10.3847/1538-4357/ac6dd9

Investigating the Blazar TXS 0506+056 through Sharp Multiwavelength Eyes During 2017–2019

CTA consortumu

The Astrophysical Journal 2022年3月

DOI： 10.3847/1538-4357/ac531d

A kinetics of the spinning gravitational field 査読あり

Tokonatsu Yamamoto

Publications of the Astronomical Society of Japan 73 ( 6 ) 1556 - 1562 2021年10月

出版者・発行元：Oxford University Press (OUP)

Abstract

According to the general theory of relativity, a spinning shell drags its gravitational field. Owing to this frame-dragging effect, the gravitational field rotates. The spinning field also drags particles in the field. Although this moment of force is negligibly small, its kinetics should be properly handled. In this study, we show that the spinning gravitational field generates a central force, which makes the spinning shells heavy. The observed galactic rotation is naturally described by this central force without dark matter. We describe the kinetics of the spinning field and central force.

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論文 - 山本 常夏

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論文 - 山本　常夏