Adiabatic non-resonant acceleration in magnetic turbulence and hard spectra of gamma-ray bursts

Abstract

We introduce a non-resonant acceleration mechanism arising from the second adiabatic invariant in magnetic turbulence and apply it to study the prompt emission spectra of gamma-ray bursts (GRBs). The mechanism contains both the first- and second-order Fermi acceleration, originating from the interacting turbulent reconnection and dynamo processes. It leads to a hard electron energy distribution up to a cutoff energy at the balance between the acceleration and synchrotron cooling. The sufficient acceleration rate ensures a rapid hardening of any initial energy distribution to a power-law distribution with the index $p\sim 1$, which naturally produces a low-energy photon index $\alpha \sim -1$ via the synchrotron radiation. For typical GRB parameters, the synchrotron emission can extend to a characteristic photon energy on the order of $\sim 100$ keV.

arXiv comment5 pages, 2 figures; accepted for publication in ApJL

References in corpus (40)

• The Physics of Gamma-Ray Bursts
• Reconnection in a Weakly Stochastic Field
• The Physics of Gamma-Ray Bursts and Relativistic Jets
• The Internal-Collision-Induced Magnetic Reconnection and Turbulence (ICMART) Model of Gamma-Ray Bursts
• Gamma-Ray Bursts: Progress, Problems & Prospects
• The BATSE Gamma-Ray Burst Spectral Catalog. I. High Time Resolution Spectroscopy of Bright Bursts using High Energy Resolution Data
• Simulations of Incompressible MHD Turbulence
• Steep Slopes and Preferred Breaks in GRB Spectra: the Role of Photospheres and Comptonization
• Simulations of MHD Turbulence in a Strongly Magnetized Medium
• The Complete Spectral Catalog of Bright BATSE Gamma-Ray Bursts
• Scattering of Cosmic Rays by Magnetohydrodynamic Interstellar Turbulence
• A Comprehensive Analysis of Fermi Gamma-Ray Burst Data. I. Spectral Components and Their Possible Physical Origins of LAT/GBM GRBs
• An analysis of gamma-ray burst spectral break models
• Reconciling observed GRB prompt spectra with synchrotron radiation ?
• Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations
• Fast cooling synchrotron radiation in a decaying magnetic field and $\gamma$-ray burst emission mechanism
• Constraints on the emission mechanisms of gamma-ray bursts
• Spectral properties of 438 GRBs detected by Fermi/GBM
• Afterglow Emission from Highly Collimated Jets with Flat Electron Spectra: Application to the GRB 010222 Case?
• Stochastic reacceleration of relativistic electrons by turbulent reconnection: a mechanism for cluster-scale radio emission ?
• Particle Acceleration in Turbulence and Weakly Stochastic Reconnection
• Growth of Magnetic Fields Induced by Turbulent Motions
• A model of acceleration of Anomalous Cosmic Rays by Reconnection in the Heliosheath
• The Role of Stochastic Acceleration in the Prompt Emission of Gamma-Ray Bursts: Application to Hadronic Injection
• Gamma-Ray Burst Prompt Emission Light Curves and Power Density Spectra in the ICMART Model
• Statistics of Reconnection-Driven Turbulence
• Synchrotron emission in small scale magnetic field as possible explanation for prompt emission spectra of gamma-ray bursts
• Slow Heating Model of Gamma-Ray Burst: Photon Spectrum and Delayed Emission
• Turbulent dynamo in a conducting fluid and partially ionized gas
• Electron Acceleration and Efficiency in Nonthermal Gamma-Ray Sources
• Reconnection Studies Under Different Types of Turbulence Driving
• No Universality for Electron's Power-Law Index (p) in Gamma-Ray Bursts and Other Relativistic Sources
• Relativistic MHD simulations of collision-induced magnetic dissipation in Poynting-flux-dominated jets/outflows
• Simulation of Relativistic Force-free Magnetohydrodynamic Turbulence
• A Tight $L_{\mathrm{p},\mathrm{iso}}-E_{\mathrm{p}}^{\prime }-{\Gamma }_0$ Correlation of Gamma-Ray Bursts
• Turbulent Reconnection in Relativistic Plasmas And Effects of Compressibility
• Gamma-Ray Burst Spectrum with Decaying Magnetic Field
• Spectral-Temporal Simulations of Internal Dissipation Models of Gamma-Ray Bursts
• Ultrahigh-Energy Cosmic Ray Production by Turbulence in Gamma-Ray Burst Jets and Cosmogenic Neutrinos
• Stochastic Acceleration Model of Gamma-Ray Burst with Decaying Turbulence

Cited by in corpus (30)

• 3D Turbulent Reconnection: Theory, Tests and Astrophysical Implications
• Second order Fermi reacceleration mechanisms and large scale synchrotron radio emission in intra-cluster bridges
• Low-energy Spectra of Gamma-ray Bursts from Cooling Electrons
• On the formation of density filaments in the turbulent interstellar medium
• The Origin of the Prompt Emission for Short GRB 170817A: Photosphere Emission or Synchrotron Emission?
• Particle acceleration in strong MHD turbulence
• Particle acceleration in relativistic turbulence: A theoretical appraisal
• Marginally fast cooling synchrotron models for prompt GRBs
• Simulating the transport of relativistic electrons and magnetic fields injected by radio galaxies in the intracluster medium
• Kinetic turbulence in shining pair plasma: intermittent beaming and thermalization by radiative cooling
• Revealing Gravitational Collapse in Serpens G3-G6 Molecular Cloud using Velocity Gradients
• Magnetic field amplification in supernova remnants
• Trapping of cosmic rays in MHD turbulence
• Turbulent Magnetic Field Amplification by the Interaction of Shock Wave and Inhomogeneous Medium
• Gamma-ray Bursts Induced by Turbulent Reconnection
• Non-resonant particle acceleration in strong turbulence: comparison to kinetic and MHD simulations
• Powerlaw spectra from stochastic acceleration
• Particle Energy Diffusion in Linear Magnetohydrodynamic Waves
• The Mouse Pulsar Wind Nebula
• Synchrotron radiation in $\gamma$-ray burst prompt emission
• Nonlinear aspects of stochastic particle acceleration
• On the broad-band synchrotron spectra of pulsar wind nebulae
• On the synchrotron spectrum of GRB prompt emission
• Synchrotron radiation from electrons with a pitch-angle distribution
• Probing Magnetic Fields of GRB X-ray Flares with Polarization Observations
• A sudden dramatic change and recovery of magneto-environment of a repeating fast radio burst
• Magnetic reconnection-driven turbulence and turbulent reconnection acceleration
• Statistical properties of Fermi GBM GRBs' spectra
• Acceleration of cosmic rays in presence of magnetohydrodynamic fluctuations at small scales
• Synchrotron spectra of GRB prompt emission and pulsar wind nebulae