Weak Alfv\'enic turbulence in relativistic plasmas II: Current sheets and dissipation
| Autor: | Ripperda, B., Mahlmann, J. F., Chernoglazov, A., TenBarge, J. M., Most, E. R., Juno, J., Yuan, Y., Philippov, A. A., Bhattacharjee, A. |
|---|---|
| Rok vydání: | 2021 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1017/S0022377821000957 |
| Popis: | Alfv\'{e}n waves as excited in black hole accretion disks and neutron star magnetospheres are the building blocks of turbulence in relativistic, magnetized plasmas. A large reservoir of magnetic energy is available in these systems, such that the plasma can be heated significantly even in the weak turbulence regime. We perform high-resolution three-dimensional simulations of counter-propagating Alfv\'{e}n waves, showing that an $E_{B_{\perp}}(k_{\perp}) \propto k_{\perp}^{-2}$ energy spectrum develops as a result of the weak turbulence cascade in relativistic magnetohydrodynamics and its infinitely magnetized (force-free) limit. The plasma turbulence ubiquitously generates current sheets, which act as locations where magnetic energy dissipates. We show that current sheets form as a natural result of nonlinear interactions between counter-propagating Alfv\'{e}n waves. These current sheets form due to the compression of elongated eddies, driven by the shear induced by growing higher order modes, and undergo a thinning process until they break-up into small-scale turbulent structures. We explore the formation of {current sheets} both in overlapping waves and in localized wave packet collisions. The relativistic interaction of localized Alfv\'{e}n waves induces both Alfv\'{e}n waves and fast waves and efficiently mediates the conversion and dissipation of electromagnetic energy in astrophysical systems. Plasma energization through reconnection in current sheets emerging during the interaction of Alfv\'{e}n waves can potentially explain X-ray emission in black hole accretion coronae and neutron star magnetospheres. Comment: Accepted in JPP, accompanied by Paper I: Weak Alfv\'enic turbulence in relativistic plasmas I: dynamical equations and basic dynamics of interacting resonant triads |
| Databáze: | arXiv |
| Externí odkaz: |
|