Open AccessExtragalactic MeV γ‐ray emission from cocoons of young radio galaxies
Author(s) -
Kino M.,
Kawakatu N.,
Ito H.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2007.11354.x
Subject(s) - physics , astrophysics , galaxy , radio galaxy , astronomy , galactic nuclei
Strong γ‐ray emission from cocoons of young radio galaxies is predicted for the first time. Considering the process of adiabatic injection of the shock dissipation energy and mass of the relativistic jet in active nuclei into the cocoon, while assuming thermalizing electron plasma interactions, we find that the thermal electron temperature of the cocoon is typically predicted to be of the order of ∼ MeV, and is determined only by the bulk Lorentz factor of the relativistic jet. Together with the time‐dependent dynamics of the cocoon expansion, we find that young cocoons can yield thermal bremsstrahlung emissions at energies ∼MeV.