Radiation from Relativistic Strongly Magnetized Outflows

Abstract

Relativistic strongly magnetized winds outflowing from fast-rotating compact objects like millisecond pulsars with surface magnetic fields of $\sim 10^{15}-10^{16}$ G are plausible sources of cosmological $\gamma$-ray bursts. In such winds, there are at least three regions where extremely powerful X-ray and $\gamma$-ray emission may be generated. The first radiating region is the wind photosphere that is at a distance of $\sim 10^9$ cm from the compact object. The second radiating region is at a distance of $\sim 10^{13}-10^{14}$ cm. In this region, the striped component of the wind field is transformed into large-amplitude electromagnetic waves. The third radiating region is at a distance of $\sim 10^{16}-10^{17}$ cm, where deceleration of the wind due to its interaction with an ambient medium becomes important. Radiation from all these regions is considered.

20 pages, 6 eps figures. To appear in the Proceedings of "Gamma-Ray Bursts: The First Three Minutes", eds. J. Poutanen and R. Svensson