The Progenitors of Gamma-Ray Bursts

Author(s):  
Joshua S. Bloom

This chapter discusses the object or objects responsible for gramma-ray bursts (GRBs). Until now, there are few absolute certainties with regard to the progenitors of GRBs. One clear standout is the progenitors of soft gamma-ray repeaters (SGRs) which are very obviously neutron stars. There are a number of corroborating lines of evidence for this progenitor association: (1) some well-localized SGRs are associated with supernova remnants, suggesting they are byproducts of recent supernovae; (2) there is quiescent X-ray emission from the sites of SGRs, similar to a class of neutron stars called “anomalous X-ray pulsars”; (3) Galactic SGRs tend to be found in the Galactic plane, where most young neutron stars reside; and (4) the ringdown emission after SGR pulses is periodic, with periods comparable to that of slowly rotating neutron stars (few seconds).

2020 ◽  
Vol 29 (11) ◽  
pp. 2041015
Author(s):  
John L. Friedman ◽  
Nikolaos Stergioulas

The first inspiral of two neutron stars observed in gravitational waves was remarkably close, allowing the kind of simultaneous gravitational wave and electromagnetic observation that had not been expected for several years. Their merger, followed by a gamma-ray burst and a kilonova, was observed across the spectral bands of electromagnetic telescopes. These GW and electromagnetic observations have led to dramatic advances in understanding short gamma-ray bursts; determining the origin of the heaviest elements; and determining the maximum mass of neutron stars. From the imprint of tides on the gravitational waveforms and from observations of X-ray binaries, one can extract the radius and deformability of inspiraling neutron stars. Together, the radius, maximum mass, and causality constrain the neutron-star equation of state, and future constraints can come from observations of post-merger oscillations. We selectively review these results, filling in some of the physics with derivations and estimates.


2000 ◽  
Vol 177 ◽  
pp. 703-706
Author(s):  
B. M. Gaensler

AbstractI consider the state of play regarding associations of supernova remnants (SNRs) with anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs). The three AXP/SNR associations are convincing, and are consistent with AXPs being young, low-velocity neutron stars. The three SGR/SNR associations are far more likely to be chance superpositions, and rely on SGRs being high velocity (>1000 km s−1) objects. These results imply either that AXPs evolve into SGRs, or that SGRs and AXPs represent different populations of object.


1987 ◽  
Vol 125 ◽  
pp. 477-487
Author(s):  
W. Doyle Evans ◽  
John G. Laros

Gamma-ray bursts are generally believed to originate in the vicinity of neutron stars, but the phenomenology is still not understood. In this paper we review the known characteristics of gamma bursts and give new observational results on temporal and spectral properties. We suggest that a class of repeating bursters exists that are spectrally harder than x-ray bursters but significantly softer than “classical” gamma bursts. The March 5, 1979, burst may be the prototype of this class of bursters.


2019 ◽  
Vol 487 (4) ◽  
pp. 5010-5018 ◽  
Author(s):  
L C Strang ◽  
A Melatos

Abstract Many short gamma-ray bursts (sGRBs) exhibit a prolonged plateau in the X-ray light curve following the main burst. It is shown that an X-ray plateau at the observed luminosity emerges naturally from a plerion-like model of the sGRB remnant, in which the magnetized, relativistic wind of a millisecond magnetar injects shock-accelerated electrons into a cavity confined by the sGRB blast wave. A geometry-dependent fraction of the plerionic radiation is also intercepted and reprocessed by the optically thick merger ejecta. The relative contributions of the plerion and ejecta to the composite X-ray light curve are estimated approximately with the aid of established ejecta models. The plerionic component of the electron energy spectrum is evolved under the action of time-dependent, power-law injection and adiabatic and synchrotron cooling in order to calculate the X-ray light curve analytically. The model yields an anticorrelation between the luminosity and duration of the plateau as well as a sudden cut-off in the X-ray flux, if the decelerating magnetar collapses to form a black hole. Both features are broadly consistent with the data and can be related to the surface magnetic field of the magnetar and its angular velocity at birth. The analogy with core-collapse supernova remnants is discussed briefly.


2012 ◽  
Vol 8 (S291) ◽  
pp. 483-485 ◽  
Author(s):  
Samar Safi-Harb ◽  
Gilles Ferrand ◽  
Heather Matheson

AbstractMotivated by the wealth of past, existing, and upcoming X-ray and gamma-ray missions, we have developed the first public database of high-energy observations of all known Galactic Supernova Remnants (SNRs): http://www.physics.umanitoba.ca/snr/SNRcat. The catalogue links to, and complements, other existing related catalogues, including Dave Green's radio SNRs catalogue. We here highlight the features of the high-energy catalogue, including allowing users to filter or sort data for various purposes. The catalogue is currently targeted to Galactic SNR observations with X-ray and gamma-ray missions, and is timely with the upcoming launch of X-ray missions (including Astro-H in 2014). We are currently developing the existing database to include an up-to-date Pulsar Wind Nebulae (PWNe)-dedicated webpage, with the goal to provide a global view of PWNe and their associated neutron stars/pulsars. This extensive database will be useful to both theorists to apply their models or design numerical simulations, and to observers to plan future observations or design new instruments. We welcome input and feedback from the SNR/PWN/neutron stars community.


2021 ◽  
Vol 366 (4) ◽  
Author(s):  
Zhi-Ying Liu ◽  
Fu-Wen Zhang ◽  
Si-Yuan Zhu

2000 ◽  
Vol 177 ◽  
pp. 699-702 ◽  
Author(s):  
E. V. Gotthelf ◽  
G. Vasisht

AbstractWe propose a simple explanation for the apparent dearth of radio pulsars associated with young supernova remnants (SNRs). Recent X-ray observations of young remnants have revealed slowly rotating (P∼ 10s) central pulsars with pulsed emission above 2 keV, lacking in detectable radio emission. Some of these objects apparently have enormous magnetic fields, evolving in a manner distinct from the Crab pulsar. We argue that these X-ray pulsars can account for a substantial fraction of the long sought after neutron stars in SNRs and that Crab-like pulsars are perhaps the rarer, but more highly visible example of these stellar embers. Magnetic field decay likely accounts for their high X-ray luminosity, which cannot be explained as rotational energy loss, as for the Crab-like pulsars. We suggest that the natal magnetic field strength of these objects control their subsequent evolution. There are currently almost a dozen slow X-ray pulsars associated with young SNRs. Remarkably, these objects, taken together, represent at least half of the confirmed pulsars in supernova remnants. This being the case, these pulsars must be the progenitors of a vast population of previously unrecognized neutron stars.


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