Large scale magnetic fields and their dissipation in GRB fireballs

By H. Spruit, F. Daigne, G. Drenkhahn. 2000

250 citations recorded by the source corpus.

We consider possible geometries of magnetic fields in GRB outflows, and their evolution with distance from the source. For magnetically driven outflows, with an assumed ratio of magnetic to kinetic energy density of order unity, the field strengths are sufficient for efficient production of γ -rays by synchrotron emission in the standard internal shock scenario, without the need for local generation of small scale fields. In these conditions, the MHD approximation is valid to large distances ($\ga$10 19 cm). In outflows driven by nonaxisymmetric magnetic fields, changes of direction of the field cause dissipation of magnetic energy by reconnection. Much of this dissipation takes place outside the photosphere of the outflow, and can convert a significant fraction of the magnetic energy flux into radiation.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6db7f013666702a72b5f44e82699aa24d4470e4c

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In Astronomy and Astrophysics

1. Bing Zhang
2. D. Giannios
3. B. Metzger
4. Pawan Kumar
5. E. Quataert
6. L. Sironi
7. F. Ryde
8. E. Liang

In Nuclear and High Energy Physics

1. Bing Zhang
2. D. Giannios
3. L. Sironi
4. F. Ryde
5. J. McKinney
6. B. Metzger
7. Huirong Yan
8. A. Spitkovsky

Citations in the corpus

• Swift Observations of GRB 070110: An Extraordinary X-Ray Afterglow Powered by the Central Engine (2007, background): “…of a spinning-down pulsar before deceleration is not well studied, but it may be related to the breakdown of the magneto-hydrodynamic condition in the magnetized outflow (Usov 1994; Spruit et al. 2001; Zhang & Mészáros 2002a) and powered by magnetic reconnections (Drenkhahn & Spruit 2002).”
• DISCERNING THE PHYSICAL ORIGINS OF COSMOLOGICAL GAMMA-RAY BURSTS BASED ON MULTIPLE OBSERVATIONAL CRITERIA: THE CASES OF z = 6.7 GRB 080913, z = 8.2 GRB 090423, AND SOME SHORT/HARD GRBs (2009, background): “Finally, if the GRB outflow is Poynting flux dominated (Usov 1992; Mészáros & Rees 1997; Spruit et al. 2001; Lyutikov & Blandford 2003; Liang & Noguchi 2009), the characteristic frequency of emission would take a different form and have different dependences on the ejecta parameters.”
• The Proto-Magnetar Model for Gamma-Ray Bursts (2010, background): “Following Metzger et al. (2007), we assume that RY/RL = min[0.3σ 0.15 0 , 1] for RY > Rns, based on an empirical fit to the axisymmetric relativistic MHD simulations of Bucciantini et al. (2006), which span the non-relativistic to relativistic transition.”
• Acceleration of GRB outflows by Poynting flux dissipation (2001, background): “First it provides a source of energy outside the photosphere which is converted directly into radiation, without the relatively inefficient intermediate step of internal shocks (Spruit et al. 2001, hereafter Paper I).”
• RELATIVISTIC RECONNECTION: AN EFFICIENT SOURCE OF NON-THERMAL PARTICLES (2014, background): “…& Kirk 2001; Lyubarsky 2003; Kirk & Skjæraasen 2003; Pétri & Lyubarsky 2007), jets from active galactic nuclei (AGNs; Romanova & Lovelace 1992; Giannios et al. 2009; Giannios 2013) and gammaray bursts (GRBs; Thompson 1994, 2006; Spruit et al. 2001; Lyutikov & Blandford 2003; Giannios 2008).”
• THE INTERNAL-COLLISION-INDUCED MAGNETIC RECONNECTION AND TURBULENCE (ICMART) MODEL OF GAMMA-RAY BURSTS (2010, methodology): “The MHD turbulence in a GRB ejecta is relativistic in nature.”
• A Reconnection Switch to Trigger gamma-Ray Burst Jet Dissipation (2010, background): “However, for reasonable lower limits on the baryon loading (Levinson & Eichler 2003), such a violation of ideal MHD only occurs at r 1019 cm (Spruit et al. 2001).”
• The expected thermal precursors of gamma-ray bursts in the internal shock model (2002, background): “The released energy is first injected into an optically thick wind, which is accelerated via an unknown mechanism, probably involving MHD processes (Thompson 1994; Meszaros & Rees 1997; Spruit et al. 2001) and becomes eventually relativistic.”
• Prompt emission spectra from the photosphere of a GRB (2006, background): “Depending on whether the energy is in thermal or magnetic form, one has a fireball (Paczynski 1986; Goodmann 1986) or a Poynting-flux dominated flow (Thompson 1994; Mészáros & Rees 1997; Spruit et al. 2001; Drenkhahn & Spruit 2002; Lyutikov & Blandford 2003).”
• Gamma-Ray Bursts in the Swift Era (2007, unknown): “…Medvedev & Loeb (1999), Lloyd & Petrosian (2000), Ghisellini et al. (2000),Panaitescu & Mészáros (2000), Medvedev (2000), Mészáros & Rees (2000), Spruit et al. (2001), Drenkhahn & Spruit (2002), Mészáros et al. (2002), Zhang & Mészáros (2002c), Dai & Lu (2002a), Pe’er & Waxman (2004a,…”
• Reconciling observed gamma-ray burst prompt spectra with synchrotron radiation? (2010, background): “…(1997); Daigne & Mochkovitch (1998)), or (iii) magnetic energy that can be dissipated via the reconnection of field lines (Thompson 1994; Meszaros & Rees 1997; Spruit et al. 2001; Drenkhahn & Spruit 2002; Lyutikov & Blandford 2003; Giannios & Spruit 2005) and then radiated by accelerated particles.”
• Unveiling the origin of X-ray flares in gamma-ray bursts (2010, background): “…specify the possibility that strong magnetic fields play a role during the acceleration of the outflow and the prompt emission (Thompson 1994; Spruit et al. 2001; Lyutikov & Blandford 2003), while any remaining magnetization at large distance can affect the interactions of the flow with the…”