Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-10-21
Astronomy and Astrophysics
Astrophysics
29pages, 11 figures
Scientific paper
10.1111/j.1365-2966.2008.14067.x
We discuss $\gamma$-ray emissions from the outer gap accelerators of middle-aged pulsars for part of the series of our studies. A two-dimensional electrodynamic model is used to solve the distribution of accelerating electric fields with electron and positron pair creation and radiation processes in the magnetic meridional plane. We compute the curvature radiation and the synchrotron radiation by solving the evolution of the Lorentz factor and the pitch angle. The calculated spectra are compared with observed phase-averaged spectra. We also use a three-dimensional geometrical model to discuss the pulse profiles. We argue that the outer gap of middle-aged pulsars occupies the whole region between the last-open field lines and the critical magnetic field lines, which are perpendicular to the rotational axis at the light cylinder. We assume that there is no outer gap accelerator inside the light cylinder between the rotational axis and the critical magnetic field lines. For the Geminga pulsar, we demonstrate that the outward curvature radiation dominates in the spectrum above 10 MeV, while the inward synchrotron radiation dominates below 10 MeV. We find that the computed spectrum is consistent with the observations in X-ray through $\gamma$-ray bands. With the pulse morphology of the $\gamma$-ray emissions, we argue that the inclination angle and the viewing angle for the Geminga pulsar are $\alpha\sim 50^{\circ}$ and $\xi\sim 90^{\circ}$, respectively.
Chang Hsiang Kuang
Takata Jumpei
No associations
LandOfFree
Non-thermal emissions from outer magnetospheric accelerators of middle-aged pulsars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Non-thermal emissions from outer magnetospheric accelerators of middle-aged pulsars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-thermal emissions from outer magnetospheric accelerators of middle-aged pulsars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-572700