Astroplasmas Seminar

Next seminar 

Friday, March 20, 12:30 pm, Dome Room, Peyton Hall

Title: A Modern Perspective on Pair Plasma Creation in Neutron Star Magnetospheres

Speaker: Andrey Timokhin (Janusz Gil Institute of Astronomy, University of Zielona Gora)

Abstract: The magnetospheres of pulsars are filled with dense electron–positron plasma that is responsible for essentially all their non-thermal emission. This plasma is believed to be created in electromagnetically driven electron–positron pair cascades in their polar caps, triggered by intermittent strong electric fields that accelerate charged particles to ultrarelativistic energies. These particles emit high-energy photons, which subsequently decay into electron–positron pairs. Although pair creation in neutron star magnetospheres has been studied extensively over the past six decades, only recently have we been able to model this process in a truly self-consistent way, thanks to modern numerical techniques and advances in computer hardware. The results of these simulations have already shown that several standard features of earlier models are incorrect. For example, pair discharges appear to be inherently intermittent, there are no sparks in pulsar polar caps, and radio emission may be generated directly by the discharges themselves. In this talk, I will provide an overview of the most recent developments in this field and present possible solutions to the long-standing and notoriously difficult problem of the origin of pulsar radio emission.