Characterizing the time variability in magnetized neutrino--cooled accretion disks: signatures of the gamma-ray burst central engine

Abstract

The central engine of Gamma Ray Bursts is hidden from direct probing with photons mainly due to the high densities involved. Inferences on their properties are thus made from their cosmological setting, energetics, low-energy counterparts and variability. If GRBs are powered by hypercritical accretion onto compact objects, on small spatial scales the flow will exhibit fluctuations, which could in principle be reflected in the power output of the central engine and ultimately in the high energy prompt emission. Here we address this issue by characterizing the variability in neutrino cooled accretion flows through local shearing box simulations with magnetic fields, and then convolving them on a global scale with large scale dynamical simulations of accretion disks. The resulting signature is characteristic, and sensitive to the details of the cooling mechanism, providing in principle a discriminant for GRB central engine properties.

Accepted for publication in ApJ Letters

References in corpus (11)

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Cited by in corpus (11)

• Neutrino-dominated accretion flows as the central engine of gamma-ray bursts
• Average power density spectrum of Swift long gamma-ray bursts in the observer and in the source rest frames
• Connection between maximum-work and maximum-power thermal cycles
• Possible Origin of Rapid Variability of Gamma-Ray Bursts due to Convective Energy Transfer in Hyperaccretion Disks
• Average power density spectrum of long GRBs detected with BeppoSAX/GRBM and with Fermi/GBM
• Vertical convection in neutrino-dominated accretion flows
• Variabilities of Gamma-ray Bursts from Black Hole Hyper-accretion Disks
• Search for Quasi-Periodical Oscillations in Precursors of Short and Long Gamma Ray Bursts
• Cooling-induced structure formation and evolution in collapsars
• Relativistic global solutions of neutrino-dominated accretion flows with magnetic coupling
• Average Power-Density Spectrum of short and long Fermi-GBM Gamma-Ray Bursts