Acceleration of GRB outflows by Poynting flux dissipation

By G. Drenkhahn. 2001

175 citations recorded by the source corpus.

We study magnetically powered relativistic outflows in which a part of the magnetic energy is dissipated internally by reconnection. For GRB parameters, and assuming that the reconnection speed scales with the Alfv en speed, signicant dissipation can take place both inside and outside the photosphere of the flow. The process leads to a steady increase of the flow Lorentz factor with radius. With an analytic model we show how the eciency of this process depends on GRB parameters. Estimates are given for the thermal and non-thermal radiation expected to be emitted from the photosphere and the optically thin part of the flow respectively. A critical parameter of the model is the ratio of Poynting flux to kinetic energy flux at some initial radius of the flow. For a large value (>100) the non-thermal radiation dominates over the thermal component. If the ratio is small (<40) only prompt

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/d718f066eb16bc623784846aab309759d15b74f8

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Citations in the corpus

On the relativistic magnetic reconnection (2005, methodology): “Similar models were also developed for the cosmological gamma-ray bursts (Drenkhahn 2002; Drenkhahn & Spruit 2002).”
The Proto-Magnetar Model for Gamma-Ray Bursts (2010, background): “An alternative possibility for jet acceleration is magnetic dissipation, i.e. a break-down of ideal MHD (Spruit et al. 2001; Drenkhahn 2002; Drenkhahn & Spruit 2002).”
THE INTERNAL-COLLISION-INDUCED MAGNETIC RECONNECTION AND TURBULENCE (ICMART) MODEL OF GAMMA-RAY BURSTS (2010, methodology): “In the past, the GRB prompt emission models in the MHD regime (Spruit et al. 2001; Drenkhahn 2002; Drenkhahn and Spruit 2002; Vlahakis and Königl 2003; Giannios 2008) have been “semi-fireball” like.”
The role of kink instability in Poynting-flux dominated jets (2006, background): “Better conversion within ideal MHD appears to be hard to achieve except by decollimation of the flow (Li et al. 1992; Begelman and Li 1994, Bogovalov 2001; Daigne and Drenkhahn 2002; but see claims to the contrary by Vlahakis and Konigl 2003a,b; Fendt and Ouyed 2004).”
The physics of gamma-ray bursts & relativistic jets (2014, background): “Let us consider a highly simplified model for reconnection where we assume, following Drenkhahn and Spruit (2002) and Drenkhahn (2002), that the reconnection speed in the comoving frame of the jet is a fraction of the Alfvén speed, i.e. the speed at which plasma from outside the current sheet flows”
QUASI-BLACKBODY COMPONENT AND RADIATIVE EFFICIENCY OF THE PROMPT EMISSION OF GAMMA-RAY BURSTS (2008, background): “Alternatively, if the outflow is Poynting-flux dominated (Drenkhahn 2002; Giannios & Spruit 2005) the dissipation occurs at magnetic reconnection sites throughout the flow.”
ASYMPTOTIC STRUCTURE OF POYNTING-DOMINATED JETS (2009, background): “On the other hand, such a flow could be accelerated further when and if the Poynting flux is dissipated (Thompson 1994; Lyubarsky & Kirk 2001; Drenkhahn 2002; Drenkhahn & Spruit 2002; Kirk & Skjæraasen 2003).”
Prompt emission spectra from the photosphere of a GRB (2006, methodology): “The notation A = 10xAx is used and the “reference values” of the model parameters are σ0 = 100, ε = 0.1, Ω = 104 rad s−1, L = 1052 erg s−1 sterad−1; very close to those used in previous studies of the model (see Drenkhahn 2002; Drenkhahn & Spruit 2002; Giannios & Spruit 2005).”
An Analysis of Gamma-Ray Burst Spectral Break Models (2002, background): “A similar proposal in the high-σ case has also been suggested (Drenkhahn 2002).”
Efficient acceleration and radiation in Poynting flux powered GRB outflows (2002, background): “The decrease of magnetic energy density with distance in such a model causes effective acceleration (Lyubarsky & Kirk 2001; Drenkhahn 2002), while at the same time providing an efficient energy source for the observed γ-rays.”
A Reconnection Switch to Trigger gamma-Ray Burst Jet Dissipation (2010, result): “1 This calculation can be compared with that in Lyubarsky & Kirk (2001) and Kirk & Skjæraasen (2003b), and also in Drenkhahn (2002) who made some simplifications to obtain their equation (31) giving their equation (37).”
Magnetic acceleration of ultrarelativistic jets in gamma-ray burst sources (2008, background): “…of Poynting flux would naturally generate a negative magnetic pressure gradient (associated with the azimuthal field component) along the flow and that this process was argued to be capable, on its own, to accelerate the flow to a high Lorentz factor (e.g. Drenkhahn & Spruit 2002; Drenkhahn 2002).”
Relativistic Magnetohydrodynamics with Application to Gamma-Ray Burst Outflows. I. Theory and Semianalytic Trans-Alfvénic Solutions (2003, methodology): “It would be interesting to combine the approach taken by these authors (see also Spruit et al. 2001 and Drenkhahn 2002) with the one utilized in this paper to consider the effects of dissipation in anonradialflow.”
Prompt GRB emission from gradual energy dissipation (2007, background): “On the other hand, if the flow contains reversing magnetic fields of sufficiently small scale, dissipation can take place directly through reconnection (Drenkhahn 2002; DS02; Thompson 2006).”
General relativistic magnetohydrodynamic simulations of the jet formation and large-scale propagation from black hole accretion systems (2006, background): “Kink instabilities have been invoked to allow reconnection-driven magnetic energy to be converted into thermal energy to accelerate the flow (Drenkhahn 2002; Drenkhahn & Spruit 2002), although the reconnection rate assumed in those papers is not supported by the GEM project on reconnection (Shay et…”