on the emission site of gamma rays from pulsars hsiang-kuang chang and cheng ho...
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On the Emission Site of Gamma On the Emission Site of Gamma Rays from PulsarsRays from Pulsars
Hsiang-Kuang Chang and Cheng HoHsiang-Kuang Chang and Cheng Ho
徐佩君徐佩君清華大學天文研究所清華大學天文研究所
• a steady cooling population of charged particles
Synchrotron radiation P=2 → Γ= 3/2
Curvature radiation P=4 → Γ= 5/3
Assumption Assumption
p
p
electronN
2
1
)(
p
photon EEN
3
1
)(
p
photon EEN
MethodMethodradiation curvature synchrotron
energy loss rate
characteristic energy of the emission
cooling time scale
dynamical time scale
The distance of the inferred emission site from the stellar center
curvature radiation
synchrotron radiation
Requiring that at the emission site
DiscussionDiscussion• Under the assumption that the gamma-ray
emission comes from a steady cooling population of charged particles, the synchrotron radiation in outer magnetospheres as the emission mechanism is consistent with the spectral behavior of most gamma-ray pulsars.
• Exception: Crab pulsar, PSR B1509-58
• The inverse Compton scattering is not considered in this method
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