Three-stage Collapse of the Long Gamma-Ray Burst from GRB 160625B Prompt Multiwavelength Observations

TL;DR

This paper presents multiwavelength observations of GRB 160625B, revealing a three-stage collapse process and quasiperiodic optical emission likely caused by a precessing, rapidly rotating superdense object evolving into a black hole.

Contribution

It introduces a novel three-stage collapse scenario for long gamma-ray bursts based on synchronized optical, X-ray, and gamma-ray data, highlighting quasiperiodic emission features.

Findings

Detection of quasi-periodic optical emission components.

Proposal of a three-stage collapse involving a superdense, precessing object.

Evidence linking optical fluctuations to the evolution of a self-gravitating body.

Abstract

This article presents the early results of synchronous multiwavelength observations of one of the brightest gamma-ray bursts (GRBs) GRB 160625B with the detailed continuous fast optical photometry of its optical counterpart obtained by MASTER and with hard X-ray and gamma-ray emission, obtained by the Lomonosov and Konus-Wind spacecraft. The detailed photometry led us to detect the quasi-periodical emission components in the intrinsic optical emission. As a result of our analysis of synchronous multiwavelength observations, we propose a three-stage collapse scenario for this long and bright GRB. We suggest that quasiperiodic fluctuations may be associated with forced precession of a self-gravitating rapidly rotating superdense body (spinar), whose evolution is determined by a powerful magnetic field. The spinar's mass allows it to collapse into a black hole at the end of evolution.