Astroplasmas Seminar

Fridays at 12:30pm, Dome Room, Peyton Hall

Next seminar

Friday, December 3rd 2021, 12.03pm

Time-dependent screening of the electric field in pulsar discharges and its implications for coherent radio emission

Elizabeth Tolman (Institute of Advanced Studies)

Abstract: Pulsars produce coherent radio emission, the source of which has remained enigmatic. Recent computational work suggests this emission may be produced in nonstationary pair plasma discharges in the pulsar polar cap, where the pulsar electric field is screened by newly-produced electron-positron pairs, leading to the production of plasma waves which escape from the magnetosphere as radio emission. In this talk, we present the physical principles governing the evolution of wave energy in the polar cap's time-dependent, relativistic, collisionless pair plasma, for both linear waves and nonlinear waves. These principles are then used to analytically determine the change in the pulsar polar cap electric field amplitude as it is screened. Finally, we discuss the implications of this model for coherent radio emission and the interpretation of pulsar observations

Scheduled seminars (September to December 2021)

24 Sept: Jens Mahlmann (Princeton University)

01 Oct: Bart Ripperda (Center for Computational Astrophysics and Princeton University)

08 Oct: David Hosking (Oxford University)

15 Oct: Ben Prather (University of Illinois)

22 Oct: Tamar Faran (The Hebrew University of Jerusalem) and Luciano Combi (Instituto Argentino de RadioastronomĂ­a)

29 Oct: Aaron Tran (Columbia University) and Itai Linial (The Hebrew University of Jerusalem)

05 Nov: Lorenzo Perrone (Cambridge University)

19 Nov: Fabio Bacchini (University of Colorado)

03 Dec: Elizabeth Tolman (Institute of Advanced Studies)

10 Dec: Elias Most (Institute of Advanced Studies and Princeton University)