Gamma Ray Burst engine activity within the quark nova scenario: Prompt emission, X-ray Plateau, and sharp drop-off

TL;DR

This paper proposes a three-stage model involving neutron stars, quark stars, and black holes to explain long gamma-ray burst emissions, X-ray afterglow plateaus, and sharp drops, aligning well with observed GRB data.

Contribution

The model introduces a novel three-stage engine involving quark star formation and collapse, providing a comprehensive explanation for GRB prompt emission and afterglow features.

Findings

Successfully explains prompt emission and X-ray plateau in GRBs

Accounts for sharp drop-offs via quark star collapse

Fits observed data from GRB 070110 and GRB 060607A

Abstract

We present a three-stage model for a long GRB inner engine to explain the prompt gamma ray emission, and interpret recent Swift satellite observations of early X-ray afterglow plateaus followed by a sharp drop off or a shallow power law decay. The three stages involves a neutron star phase, a quark star (QS) and a black hole phase as described in Staff et al. (2007). We find that the QS stage allows for more energy to be extracted from neutron star to QS conversion as well as from ensuing accretion onto the QS. The QS accretion phase naturally extends the engine activity and can account for both the prompt emission and irregular early X-ray afterglow activity. Following the accretion phase, the QS can spin-down by emission of a baryon-free outflow. The magnetar-like magnetic field strengths resulting from the NS to QS transition provide enough spin-down energy, for the correct amount of time, to account for the plateau in the X-ray afterglow. In our model, a sharp drop-off following the plateau occurs when the QS collapses to a BH during the spin-down, thus shutting-off the secondary outflow. We applied our model to GRB 070110 and GRB 060607A and found that we can consistently account for the energetics and duration during the prompt and plateau phases.