THREE-DIMENSIONAL RELATIVISTIC PAIR PLASMA RECONNECTION WITH RADIATIVE FEEDBACK IN THE CRAB NEBULA

The discovery of rapid synchrotron gamma-ray flares above 100 MeV from the Crab Nebula has attracted new interest in alternative particle acceleration mechanisms in pulsar wind nebulae. Diffuse shock-acceleration fails to explain the flares because particle acceleration and emission occur during a s...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2014-02, Vol.782 (2), p.1-15
Main Authors: Cerutti, B, Werner, G R, Uzdensky, D A, Begelman, M C
Format: Article
Language:English
Subjects:
ACCELERATION
ASTROPHYSICS, COSMOLOGY AND ASTRONOMY
Beams (radiation)
CRAB NEBULA
ELECTRIC FIELDS
EMISSION
ENERGY LOSSES
FEEDBACK
Flares
GAMMA RADIATION
KINK INSTABILITY
MAGNETIC FLUX
MAGNETIC RECONNECTION
MEV RANGE
Particle acceleration
Particle beams
PLASMA
PLASMA HEATING
RELATIVISTIC RANGE
SIMULATION
SYNCHROTRON RADIATION
SYNCHROTRONS
Three dimensional
THREE-DIMENSIONAL CALCULATIONS
Two dimensional
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The discovery of rapid synchrotron gamma-ray flares above 100 MeV from the Crab Nebula has attracted new interest in alternative particle acceleration mechanisms in pulsar wind nebulae. Diffuse shock-acceleration fails to explain the flares because particle acceleration and emission occur during a single or even sub-Larmor timescale. In this regime, the synchrotron energy losses induce a drag force on the particle motion that balances the electric acceleration and prevents the emission of synchrotron radiation above 160 MeV. Previous analytical studies and two-dimensional (2D) particle-in-cell (PIC) simulations indicate that relativistic reconnection is a viable mechanism to circumvent the above difficulties. The reconnection electric field localized at X-points linearly accelerates particles with little radiative energy losses. In this paper, we check whether this mechanism survives in three dimension (3D), using a set of large PIC simulations with radiation reaction force and with a guide field. In agreement with earlier works, we find that the relativistic drift kink instability deforms and then disrupts the layer, resulting in significant plasma heating but few non-thermal particles. A moderate guide field stabilizes the layer and enables particle acceleration. We report that 3D magnetic reconnection can accelerate particles above the standard radiation reaction limit, although the effect is less pronounced than in 2D with no guide field. We confirm that the highest-energy particles form compact bunches within magnetic flux ropes, and a beam tightly confined within the reconnection layer, which could result in the observed Crab flares when, by chance, the beam crosses our line of sight.
ISSN:0004-637X
1538-4357
DOI:10.1088/0004-637X/782/2/104