Open AccessA new mechanism for pulsar gamma‐ray emission
Author(s) -
Machabeli G. Z.,
Luo Qinghuan,
Melrose D. B.,
Vladimirov S.
Publication year - 2000
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 - 10.1046/j.1365-8711.2000.03114.x
Subject(s) - physics , pulsar , pitch angle , synchrotron radiation , perpendicular , astrophysics , plasma , particle (ecology) , synchrotron , gamma ray , radiation , atomic physics , computational physics , optics , astronomy , nuclear physics , oceanography , geometry , mathematics , geology
Gamma‐ray emission in pulsar magnetospheres is attributed to synchrotron radiation, which tends to decrease the pitch angle of the particle, being balanced by plasma processes tending to increase the pitch angle. The plasma processes are non‐resonant instabilities that drive non‐resonant quasilinear diffusion (NQD), thereby pumping energy from waves and the parallel motion of the particle into the perpendicular motion of the particle. It is shown that NQD can maintain the pitch angles for particles near the light‐cylinder such that they radiate synchrotron radiation at MeV energies. Compared to conventional emission mechanisms (such as polar cap or outer gap models), the resulting spectrum has a relatively low upper cut‐off from about a few to 100 MeV. Possible observational consequences of this mechanism are discussed.