著者

Alan Davidson

出版者

Oxford University Press

巻号頁・発行日

2014

著者

Maiken Umbach

出版者

Oxford University Press

巻号頁・発行日

2009

著者

Anthony J. Lisska

出版者

Oxford University Press

巻号頁・発行日

2016

著者

Miki Yohei Umemura Masayuki

出版者

Oxford University Press

雑誌

Monthly notices of the Royal Astronomical Society (ISSN:00358711)

巻号頁・発行日

vol.475, no.2, pp.2269-2281, 2018-04

被引用文献数

20

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Providing initial conditions is an essential procedure for numerical simulations of galaxies. The initial conditions for idealized individual galaxies in N-body simulations should resemble observed galaxies and be dynamically stable for time-scales much longer than their characteristic dynamical times. However, generating a galaxy model ab initio as a system in dynamical equilibrium is a difficult task, since a galaxy contains several components, including a bulge, disc, and halo. Moreover, it is desirable that the initial-condition generator be fast and easy to use. We have now developed an initial-condition generator for galactic N-body simulations that satisfies these requirements. The developed generator adopts a distribution-function-based method, and it supports various kinds of density models, including custom-tabulated inputs and the presence of more than one disc. We tested the dynamical stability of systems generated by our code, representing early- and late-type galaxies, with N = 2097 152 and 8388 608 particles, respectively, and we found that the model galaxies maintain their initial distributions for at least 1 Gyr. The execution times required to generate the two models were 8.5 and 221.7 seconds, respectively, which is negligible compared to typical execution times for N-body simulations. The code is provided as open-source software and is publicly and freely available at https://bitbucket.org/ymiki/magi.

著者

Jeffrey Brodd ...

出版者

Oxford University Press

巻号頁・発行日

2013

著者

HEDBERG Bo

出版者

Oxford University Press

雑誌

Handbook of Organizational Design (1)

巻号頁・発行日

pp.3-27, 1981

被引用文献数

1

著者

edited by Nancy E. Snow

出版者

Oxford University Press

巻号頁・発行日

2018

著者

Richard Salomon

出版者

Oxford University Press

巻号頁・発行日

1998

出版者

Oxford University Press

巻号頁・発行日

2011

著者

edited by Roger Brock and Stephen Hodkinson

出版者

Oxford University Press

巻号頁・発行日

2000

著者

by Ioannis Kokkoris Howard Shelanski

出版者

Oxford University Press

巻号頁・発行日

2014

著者

Thomas F. Scanlon

出版者

Oxford University Press

巻号頁・発行日

2002

著者

Arthur M. Sackler Gallery Smithsonian Institution

出版者

Oxford University Press

巻号頁・発行日

1987

著者

W. H. Whiteley M. G. Muli

出版者

Oxford University Press

巻号頁・発行日

1962

著者

Takahashi Rohta Umemura Masayuki

出版者

Oxford University Press

雑誌

Monthly Notices of the Royal Astronomical Society (ISSN:00358711)

巻号頁・発行日

vol.464, no.4, pp.4567-4585, 2017-02

被引用文献数

12

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We present a general relativistic radiative transfer code, ARTIST (Authentic Radiative Transfer In Space–Time), that is a perfectly causal scheme to pursue the propagation of radiation with absorption and scattering around a Kerr black hole. The code explicitly solves the invariant radiation intensity along null geodesics in the Kerr–Schild coordinates, and therefore properly includes light bending, Doppler boosting, frame dragging, and gravitational redshifts. The notable aspect of ARTIST is that it conserves the radiative energy with high accuracy, and is not subject to the numerical diffusion, since the transfer is solved on long characteristics along null geodesics. We first solve the wavefront propagation around a Kerr black hole that was originally explored by Hanni. This demonstrates repeated wavefront collisions, light bending, and causal propagation of radiation with the speed of light. We show that the decay rate of the total energy of wavefronts near a black hole is determined solely by the black hole spin in late phases, in agreement with analytic expectations. As a result, the ARTIST turns out to correctly solve the general relativistic radiation fields until late phases as t ∼ 90 M. We also explore the effects of absorption and scattering, and apply this code for a photon wall problem and an orbiting hotspot problem. All the simulations in this study are performed in the equatorial plane around a Kerr black hole. The ARTIST is the first step to realize the general relativistic radiation hydrodynamics.

著者

edited by T.G. Benson

出版者

Oxford University Press

巻号頁・発行日

1964

著者

edited by M. Cary ... [et al.] with the assistance of H.J. Rose H.P. Harvey A. Souter

出版者

Oxford University Press

巻号頁・発行日

1949

著者

general editors Simon Hornblower and Antony Spawforth assistant editor Esther Eidinow

出版者

Oxford University Press

巻号頁・発行日

2012

著者

David Benatar

出版者

Oxford University Press

巻号頁・発行日

2006

著者

Eta Harich-Schneider

出版者

Oxford University Press

巻号頁・発行日

1973