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

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.

Global MASTER-Net Highlights

“…Thus, the work is devoted to the interpretation of synchronous multiwavelength observations of the gamma-ray burst GRB 160625B by Russian space and ground systems [13,27] On June 25, 2016, one of the brightest flares in the history of GRB observations -GRB 160625B, occurred. The most detailed optical observations were made by the Global Network of Robotic Telescopes of Moscow State University MASTER.…”

“…Extreme phenomena still have many problems and have been studied very intensively in recent years . The effective ways of their studing involve using multichannel and multi-wavelength observations by fully robotic telescopes, distributed by Earth for full time control of near and far space like MASTER Global Robotic Net [12][13][14][15][16]19,20,[22][23][24][25][26][27]35,43,47,[49][50][51]67,[85][86][87][88][89][90][91].…”

“…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 during prompt stage may be associated with forced precession of a self-gravitating rapidly rotating superdense body (spinar [27], Figure 10 ), 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.…”

“…After the outstanding discovery of the intrinsic optical emission of 8th magnitude gamma-ray bursts (Akerloff et al in 1999 [11]), it became clear that extreme processes can be observed with the smallest but robotic telescopes. Since 2002, the MASTER team (Lipunov, 2003 [12]) has joined the search for superpowerful phenomena in the Universe, which has discovered more than 3500 optical flares in the Universe to date [12][13][14][15][16][17][18][19][20][22][23][24][25][26][27]. Among the most significant discoveries there were the discovery of the polarization of the intrinsic optical emission of gamma-ray bursts (Troja et al in 2017 [13]) and the independent discovery of the kilonova GW170817 (Lipunov et al in 2017 [14-17]) .…”

The Purple Mountain Observatory and Modernization of Chinese Astronomy

“…All MASTER telescopes have identical optical schemes and are equipped with identical sets of polarization and BVRI filters (Kornilov et al 2012;Pruzhinskaya et al 2014;Lipunov et al 2017Lipunov et al , 2019Lipunov et al , 2022, enabling the derivation of a target light curve within one photometric framework (Lipunov et al 2010(Lipunov et al , 2023Troja et al 2017;Kornilov et al 2012;Gorbovskoy et al 2010). White light magnitudes are calculated using the equation W = 0.2B + 0.8R (Lipunov et al 2017).…”