Central engine afterglow of Gamma-ray Bursts

TL;DR

This paper reviews the evolving understanding of gamma-ray burst afterglows, emphasizing the role of the central engine in producing afterglow components, a shift from the earlier external shocks model.

Contribution

It highlights the recognition of central engine activity as a key contributor to GRB afterglows, marking a significant update in the theoretical framework.

Findings

Central engine activity explains certain afterglow components.

Shift from external shocks to central engine models post-2004.

The interpretation by Katz, Piran & Sari is now widely accepted.

Abstract

Before 2004, nearly all GRB afterglow data could be understood in the context of the external shocks model. This situation has changed in the past two years, when it became clear that some afterglow components should be attributed to the activity of the central engine; i.e., the {\it central engine afterglow}. We review here the afterglow emission that is directly related to the GRB central engine. Such an interpretation proposed by Katz, Piran & Sari, peculiar in pre-{\it Swift} era, has become generally accepted now.