Pair creation from radial electromagnetic perturbation of a compact astrophysical object

TL;DR

This paper explores a new mechanism for pair creation on compact astrophysical objects' surfaces, involving radial perturbations that lead to electron-positron pair bursts or continuous creation depending on the perturbation scale.

Contribution

It introduces an alternative hypothesis linking surface perturbations to pair creation, highlighting the dependence on perturbation scale relative to mean free path.

Findings

Pair creation occurs via collisionless plasma oscillations when perturbation scale is comparable to mean free path.

Continuous pair creation results from thermalized perturbations with larger scales.

The mechanism's relevance is discussed in various astrophysical contexts.

Abstract

Recently Usov's mechanism of pair creation on the surface of compact astrophysical objects has been revisited [1] with a conclusion that the pair creation rate was previously underestimated in the literature by nearly two orders of magnitude. Here we consider an alternative hypothesis of pair creation due to a perturbation of the surface of a compact object. Radial perturbation is induced in hydrodynamic velocity resulting in a microscopic displacement of the negatively charged component with respect to the positively charged one. The result depends on the ratio between the spatial scale of the perturbation $\lambda$ and the mean free path $l$. When $\lambda\sim l$ the perturbation energy is converted into a burst of electron-positron pairs which are created in collisionless plasma oscillations at the surface; after energy excess is dissipated electrosphere returns to its electrostatic configuration. When instead $\lambda\gg l$, the perturbation is thermalized, its energy is transformed into heat, and pairs are created continuously by the heated electrosphere. We discuss the relevant astrophysical scenarios.