Speaker
Benoit Cerutti
(Princeton University)
Description
Pulsars shine throughout the electromagnetic spectrum, from radio waves to energetic gamma rays. The radio emission is thought to originate from the discharge of the polar-cap and the formation of copious electron-positron pairs. Gamma rays are traditionally associated with particle acceleration in electrostatic gaps within the light cylinder. The recent development of global Particle-In-Cell (PIC) simulations of the pulsar magnetosphere enables to test these scenarios self-consistently. We show that general relativistic effects, most notably frame-dragging, are essential to ignite pair creation in the polar cap for low-inclination pulsars, and hence enable pulsars to emit radio waves. In addition, three-dimensional radiative PIC simulations indicate that the current sheet that forms beyond the light cylinder is the main site of particle acceleration in plasma-filled pulsars, instead of gaps within the co-rotating magnetosphere. Relativistic reconnection dissipates the magnetic energy which is then converted to energetic particles and high-energy synchrotron radiation. We present self-consistent modeling of pulsar gamma-ray lightcurves and spectra obtained directly from the kinetic simulations, and discuss the results in the context of observed gamma-ray pulsars.
Author
Benoit Cerutti
(Princeton University)
Co-authors
Alexander Philippov
(Princeton University)
Anatoly Spitkovsky
(Princeton University)
