RELATIVISTIC RECONNECTION: AN EFFICIENT SOURCE OF NON-THERMAL PARTICLES

By L. Sironi, A. Spitkovsky. 2014

440 citations recorded by the source corpus.

In magnetized astrophysical outflows, the dissipation of field energy into particle energy via magnetic reconnection is often invoked to explain the observed non-thermal signatures. By means of two- and three-dimensional particle-in-cell simulations, we investigate anti-parallel reconnection in magnetically dominated electron–positron plasmas. Our simulations extend to unprecedentedly long temporal and spatial scales, so we can capture the asymptotic state of the system beyond the initial transients, and without any artificial limitation by the boundary conditions. At late times, the reconnection layer is organized into a chain of large magnetic islands connected by thin X-lines. The plasmoid instability further fragments each X-line into a series of smaller islands, separated by X-points. At the X-points, the particles become unmagnetized and they get accelerated along the reconnection electric field. We provide definitive evidence that the late-time particle spectrum integrated over the whole reconnection region is a power law whose slope is harder than −2 for magnetizations σ ≳ 10. Efficient particle acceleration to non-thermal energies is a generic by-product of the long-term evolution of relativistic reconnection in both two and three dimensions. In three dimensions, the drift-kink mode corrugates the reconnection layer at early times, but the long-term evolution is controlled by the plasmoid instability which facilitates efficient particle acceleration, analogous to the two-dimensional physics. Our findings have important implications for the generation of hard photon spectra in pulsar winds and relativistic astrophysical jets.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/d4938a84f18488e3a914ad2fad0afb6ac77ec03c

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The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. L. Sironi
2. B. Metzger
3. A. Spitkovsky
4. D. Giannios
5. B. Margalit
6. M. Petropoulou
7. A. Philippov
8. B. Cerutti

In Atomic and Molecular Physics, and Optics

1. L. Sironi
2. D. Giannios
3. M. Petropoulou
4. U. Keshet
5. M. Lemoine
6. A. Philippov
7. Hui Li
8. B. Cerutti

In Nuclear and High Energy Physics

1. L. Sironi
2. D. Giannios
3. A. Spitkovsky
4. M. Petropoulou
5. A. Philippov
6. B. Cerutti
7. U. Keshet
8. M. Lemoine

Citations in the corpus

• Ab-initio Pulsar Magnetosphere: Particle Acceleration in Oblique Rotators and High-energy Emission Modeling (2017, background): “8 tivistic magnetic reconnection (Sironi & Spitkovsky 2014; Guo et al. 2014; Werner et al. 2016b).”
• PARTICLE ACCELERATION AND PLASMA DYNAMICS DURING MAGNETIC RECONNECTION IN THE MAGNETICALLY DOMINATED REGIME (2015, methodology): “Using total relativistic energy in the energy spectra significantly distorts the spectral index in the energy range of 0 < γ − 1 < 10, which may alter the interpretation of the results (Sironi & Spitkovsky 2014; Melzani et al. 2014b; Werner et al. 2014)‡.”
• Particle acceleration in axisymmetric pulsar current sheets (2014, neutral): “H E ] 7 J an 2 01 5 Sironi & Spitkovsky 2014; Guo et al. 2014; Werner et al. 2014).”
• A hadronic origin for ultra-high-frequency-peaked BL Lac objects (2014, background): “Another mechanism for efficiently accelerating particles is magnetic reconnection; in this case as well it is possible to obtain hard (α ' 1.5) particle energy distributions (see e.g. Cerutti et al. 2012; Sironi & Spitkovsky 2014).”
• Plasmoids in relativistic reconnection, from birth to adulthood: first they grow, then they go (2016, background): “…Nalewajko et al. 2015; Sironi et al. 2015; Werner et al. 2016; Kagan et al. 2016) and three dimensions (3D; e.g., Zenitani & Hoshino 2005, 2008; Yin et al. 2008; Liu et al. 2011; Sironi & Spitkovsky 2011a, 2012; Kagan et al. 2013; Cerutti et al. 2013b; Sironi & Spitkovsky 2014; Guo et al. 2015).”
• Non-thermal particle acceleration in collisionless relativistic electron-proton reconnection (2016, background): “…Lyubarsky & Liverts 2008; Jaroschek & Hoshino 2009; Liu et al. 2011; Bessho & Bhattacharjee 2012; Kagan et al. 2013; Cerutti et al. 2012b, 2013, 2014a,b; Sironi & Spitkovsky 2011, 2014; Guo et al. 2014, 2015; Liu et al. 2015; Nalewajko et al. 2015; Sironi et al. 2015, 2016; Werner et al. 2016).”
• Relativistic Jets Shine through Shocks or Magnetic Reconnection (2015, methodology): “…drift-kink mode corrugates the reconnection layer at early times (Daughton 1998; Zenitani & Hoshino 2008), but the long-term evolutionis controlled by the plasmoid instability, that facilitates efficient particle acceleration, in analogy to the two-dimensional physics (Sironi & Spitkovsky 2014).”
• Modelling high-energy pulsar light curves from first principles (2015, positive): “These plasma instabilities could be similar to the tearing and kink modes usually observed in local 3D PIC simulations of relativistic reconnection (e.g., Zenitani & Hoshino 2008; Cerutti et al. 2014; Sironi & Spitkovsky 2014).”
• Relativistic Shocks: Particle Acceleration and Magnetization (2015, background): “Indeed, hard particle spectra are found to be a generic by-product of magnetic reconnection in the relativistic regime appropriate for pulsar winds (Sironi and Spitkovsky 2014; Sironi et al. 2015, see also Kagan et al. (2015) in the present volume).”
• Millisecond Magnetar Birth Connects FRB 121102 to Superluminous Supernovae and Long-duration Gamma-Ray Bursts (2017, background): “…in the striped pulsar wind (e.g. Sironi & Spitkovsky 2011; Zrake & Arons 2016), which particle-in-cell plasma simulations show can indeed produce flatter (p < 2) electron spec- tra (e.g., Sironi & Spitkovsky 2014), consistent with that needed to explain a flatter spectral index β ≈ −0.2.”