Summary:

Electrospheres are environments with the same origin as pulsars: a highly magnetized rotating neutron star. In pulsars, a cascade of electron-positron pair creation enriches the plasma. The plasma surrounding an electrosphere consists solely of particles that have escaped from the surface of the neutron star. Most of the 300 million presumed neutron stars in the Galaxy are not pulsars, but are surrounded by an electrosphere. Electrospheres are therefore fairly common objects, despite their low luminosity, which has so far prevented direct observation.

Electrospheres whose magnetic axis is aligned with the rotation axis have been well described for decades. The case of a magnetic axis oblique to the axis of rotation has resisted much theoretical research. We aimed at studying the physics of aligned and oblique electrospheres using a dedicated numerical simulation code which would enable ab initio simulations with realistic neutron star parameters. This code has recently been completed. Several numerical simulations have been carried out.

In this seminar, we briefly introduce the numerical simulation code and show the results of a parametric study. Many oblique electrospheres have the a structure analogous to those of the aligned electrospheres already known, but others have more specific properties. Some of them can enrich the interstellar medium with a plasma of ions and electrons.

For more information please contact Marcowith A.