The puzzling temporally variable optical and X-ray afterglow of GRB 101024A

TL;DR

This paper analyzes the unusual optical and X-ray afterglow of GRB 101024A, revealing complex temporal behavior that challenges standard models and suggests possible magnetar formation.

Contribution

It presents early optical observations combined with X-ray data and discusses the afterglow's complex features within the reverse shock/forward shock framework, proposing energy injection or magnetar formation as explanations.

Findings

Optical afterglow shows an extremely steep decay with alpha~5.

A plateau phase is observed in both optical and X-ray light curves.

The observations suggest energy injection or magnetar formation.

Abstract

Aim: To present the optical observations of the afterglow of GRB 101024A and to try to reconcile these observations with the X-ray afterglow data of GRB 101024A using current afterglow models Method: We employ early optical observations using the Zadko Telescope combined with X-ray data and compare with the reverse shock/forward shock model. Results: The early optical light curve reveals a very unusual steep decay index of alpha~5. This is followed by a flattening and possibly a plateau phase coincident with a similar feature in the X-ray. We discuss these observations in the framework of the standard reverse shock/forward shock model and energy injection.We note that the plateau phase might also be the signature of the formation of a new magnetar.