Torsional oscillations of strange stars

TL;DR

This paper models torsional oscillations of strange stars with a bare quark surface, estimating their electromagnetic emission and suggesting they could be extremely bright, detectable sources in the universe.

Contribution

It introduces simple models of strange stars with a bare quark surface and analyzes their torsional oscillations and electromagnetic emission.

Findings

Estimated emitted power of about 10^45 erg/s

Oscillation relaxation times range from microseconds to minutes

Potentially detectable electromagnetic signals from strange stars

Abstract

Strange stars are one of the hypothetical compact stellar objects that can be formed after a supernova explosion. The existence of these objects relies on the absolute stability of strange {\it collapsed} quark matter with respect to standard nuclear matter. We discuss simple models of strange stars with a bare quark matter surface, thus standard nuclear matter is completely absent. In these models an electric dipole layer a few hundreds Fermi thick should exist close to the star surface. Studying the torsional oscillations of the electrically charged layer we estimate the emitted power, finding that it is of the order of $10^{45}$ erg/s, meaning that these objects would be among the brightest compact sources in the heavens. The associated relaxation times are very uncertain, with values ranging between microseconds and minutes, depending on the crust thickness. Although part of the radiated power should be absorbed by the electrosphere surrounding the strange star, a sizable fraction of photons should escape and be detectable.