### Abstract

We present numerical attempts of radiative transfer in a relativistic scattering flow that can produce gamma rays using a three-dimensional Monte Carlo code. We prepared an initial background flowfield obtained from hydrodynamical simulation of a relativistic jet in which Thomson scattering dominates compared to absorption, and solved the radiative transfer equation for the background evolved by a simple expansion model. Since a large number of sample particles is required for an accurate computation, we have parallelized the Monte Carlo code in order to obtain solutions in a practical computational time even for a long-term simulation coupled with a time-dependent flowfield. Using this code, higher parallel efficiency is achieved with larger number of particles. The obtained light curve from the simple model shows a signal of the transition from the opaque post-shock flow to the transparent regime as the flow expands, and the high-energy photons are generated by not only the Doppler boosting but also the inverse Compton scattering.

Original language | English |
---|---|

Pages (from-to) | 280-287 |

Number of pages | 8 |

Journal | High Energy Density Physics |

Volume | 9 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2013 Jun |

### Fingerprint

### Keywords

- Gamma-ray burst
- Monte Carlo method
- Radiative transfer
- Relativistic jet

### ASJC Scopus subject areas

- Nuclear and High Energy Physics
- Radiation

### Cite this

*High Energy Density Physics*,

*9*(2), 280-287. https://doi.org/10.1016/j.hedp.2013.01.002

**Parallel computing of radiative transfer in relativistic jets using Monte Carlo method.** / Ishii, Ayako; Ohnishi, Naofumi; Nagakura, Hiroki; Ito, Hirotaka; Yamada, Shoichi.

Research output: Contribution to journal › Article

*High Energy Density Physics*, vol. 9, no. 2, pp. 280-287. https://doi.org/10.1016/j.hedp.2013.01.002

}

TY - JOUR

T1 - Parallel computing of radiative transfer in relativistic jets using Monte Carlo method

AU - Ishii, Ayako

AU - Ohnishi, Naofumi

AU - Nagakura, Hiroki

AU - Ito, Hirotaka

AU - Yamada, Shoichi

PY - 2013/6

Y1 - 2013/6

N2 - We present numerical attempts of radiative transfer in a relativistic scattering flow that can produce gamma rays using a three-dimensional Monte Carlo code. We prepared an initial background flowfield obtained from hydrodynamical simulation of a relativistic jet in which Thomson scattering dominates compared to absorption, and solved the radiative transfer equation for the background evolved by a simple expansion model. Since a large number of sample particles is required for an accurate computation, we have parallelized the Monte Carlo code in order to obtain solutions in a practical computational time even for a long-term simulation coupled with a time-dependent flowfield. Using this code, higher parallel efficiency is achieved with larger number of particles. The obtained light curve from the simple model shows a signal of the transition from the opaque post-shock flow to the transparent regime as the flow expands, and the high-energy photons are generated by not only the Doppler boosting but also the inverse Compton scattering.

AB - We present numerical attempts of radiative transfer in a relativistic scattering flow that can produce gamma rays using a three-dimensional Monte Carlo code. We prepared an initial background flowfield obtained from hydrodynamical simulation of a relativistic jet in which Thomson scattering dominates compared to absorption, and solved the radiative transfer equation for the background evolved by a simple expansion model. Since a large number of sample particles is required for an accurate computation, we have parallelized the Monte Carlo code in order to obtain solutions in a practical computational time even for a long-term simulation coupled with a time-dependent flowfield. Using this code, higher parallel efficiency is achieved with larger number of particles. The obtained light curve from the simple model shows a signal of the transition from the opaque post-shock flow to the transparent regime as the flow expands, and the high-energy photons are generated by not only the Doppler boosting but also the inverse Compton scattering.

KW - Gamma-ray burst

KW - Monte Carlo method

KW - Radiative transfer

KW - Relativistic jet

UR - http://www.scopus.com/inward/record.url?scp=84874570012&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84874570012&partnerID=8YFLogxK

U2 - 10.1016/j.hedp.2013.01.002

DO - 10.1016/j.hedp.2013.01.002

M3 - Article

AN - SCOPUS:84874570012

VL - 9

SP - 280

EP - 287

JO - High Energy Density Physics

JF - High Energy Density Physics

SN - 1574-1818

IS - 2

ER -