Theoretical Study of Physical Processes and Interactions in Large Scale Jets

大型射流物理过程和相互作用的理论研究

• 批准号: 16540215
• 负责人: TAKAHARA Fumio
• 金额: $ 1.09万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540215/
• 关键词: Relativistic Hydrodynamics; Particle Acceleration; Shock Waves; Radio Galaxies; Synchrotron Radiation; Compton Scattering; Electron Positron Pairs

X-ray emission from large scale jets is interpreted as synchrotron emission for FR-I radio galaxies and inverse Compton scattering of CMB photons for FR-II galaxies, respectively. However, quantitative estimates of bulk Lorentz factor and magnetic field strength are largely affected by internal structure of jets. Detailed investigations on Cen-A jets are made to show that particle acceleration in the interaction region between jet surface and surroundings plays an important role. We proposed a reflection model for the orphan TeV flare observed for 1959+650, which also implies the importance of internal structure of jets.We have also made the following researches on relevant physical processes.1.Dynamical consideration of internal shocks indicates that the rest mass density of the jet matter is about thousand times larger than that of relativistic electrons.2.Relativistic beaming effects on apparent structure on polarization and brightness map are not simple, which should be taken into account in the interpretation of observations.3.Klein-Nishina effect in Compton scattering can largely modify the electron spectrum and in some cases it does not necessarily lead to a strong decrease of radiation intensity.4.We discussed the formation mechanism and instability of electron-positron beams.

大尺度喷流的X射线辐射被解释为FR-I射电星系的同步辐射和FR-II星系的CMB光子的逆康普顿散射。然而，体洛伦兹因子和磁场强度的定量估计在很大程度上受到喷流内部结构的影响。对Cen-A射流的研究表明，射流表面与周围环境相互作用区的粒子加速起着重要的作用。我们提出了1959+650年TeV孤儿耀斑的反射模型，我们还对有关的物理过程作了如下研究：1.内激波的动力学考虑表明，喷流物质的静止质量密度比相对论电子的静止质量密度大几千倍; 2.相对论聚束效应对喷流表观结构的影响3.康普顿散射中的Klein-Nishina效应对电子能谱有很大的修正作用，但在某些情况下并不一定导致辐射强度的强烈下降。4.讨论了正负电子束的形成机制和不稳定性。

项目成果

Giant Flare of SGR 1806-20 from a Relativistic Jet

• DOI: 10.1093/pasj/57.3.l11
• 发表时间: 2005-02
• 作者: R. Yamazaki;K. Ioka;F. Takahara;N. Shibazaki

Constraints on the energetics and plasma composition of relativistic jets in FR II sources

• DOI: 10.1111/j.1365-2966.2004.07511.x
• 发表时间: 2003-12
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: M. Kino;F. Takahara

Compton Scattering in the Klein-Nishina Regime Revisited

• DOI: 10.1086/427405
• 发表时间: 2005-03
• 期刊: The Astrophysical Journal
• 作者: M. Kusunose;F. Takahara

The X-Ray Jet in Centaurus A: Clues on the Jet Structure and Particle Acceleration

半人马座 A 中的 X 射线射流：有关射流结构和粒子加速的线索

• 发表时间: 2006
• 期刊: Astrophysical Journal 641・1
• 作者: Broadhurst;T.;Takada;M.;Umetsu;K.;Kong;X.;Arimoto;N.;Chiba;M.;Futamase;T.;T.Kato;J.Kataoka
• 通讯作者: J.Kataoka

Electric field screening by a proton counterflow in the pulsar polar cap

脉冲星极帽中质子逆流的电场屏蔽

• 发表时间: 2005
• 期刊: Astronomy and Astrophysics 428,1
• 作者: Broadhurst;T.;Takada;M.;Umetsu;K.;Kong;X.;Arimoto;N.;Chiba;M.;Futamase;T.;T.Kato;J.Kataoka;T.Kato;J.Kataoka;T.Kato;J.Kataoka;K.Asano
• 通讯作者: K.Asano