An emission mechanism for extragalactic radio jets

The observed emtsswns of radio waves from extragalactic radio jets are customarily interpreted in terms of the incoherent synchrotron radiation produced by a nonthermal population of relativistic electrons (or positrons) gyrating in a magnetic field. Such an interpretation requires, by necessity, a...

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Detalles Bibliográficos
Autores: Yoon, Peter H., Ziebell, Luiz Fernando
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1996
País:Brasil
Institución:Universidade Federal do Rio Grande do Sul (UFRGS)
Repositorio:Repositório Institucional da UFRGS
Idioma:inglés
OAI Identifier:oai:www.lume.ufrgs.br:10183/108765
Acceso en línea:http://hdl.handle.net/10183/108765
Access Level:acceso abierto
Palabra clave:Plasmas astrofisicos
Jatos astrofísicos
Magneto-hidrodinâmica
Radiogalaxias
Propagação de ondas de rádio
Nucleo galatico
Aceleration of particles
Galaxies: jets
MHD
Radiation mechanisms : nonthermal
Descripción
Sumario:The observed emtsswns of radio waves from extragalactic radio jets are customarily interpreted in terms of the incoherent synchrotron radiation produced by a nonthermal population of relativistic electrons (or positrons) gyrating in a magnetic field. Such an interpretation requires, by necessity, a mechanism (or mechanisms) to constantly reenergize the particles in directions transverse to the magnetic field in momentum space. This paper, on the other hand, presents a possible alternative mechanism for radiation emission that does not require transverse reacceleration, albeit the theory is only preliminary at this stage. The emission mechanism described in the present paper is an induced plasma process that results from a nonlinear coupling of the electrostatic beam mode with the transverse electromagnetic mode. The beam mode is excited when a stream of ultrarelativistic electron-positron pair plasma nonlinearly interacts with low-frequency intrinsic turbulence. The only source of free energy for the instability is the streaming motion of the pair plasma. Therefore, as opposed to the incoherent synchrotron model, this mechanism (if, indeed, it is operative) has an advantage of not having to rely on the concept of constant renenergization of particles in the transverse direction.