Turbulence in Astrophysical Environments

Coordinators: Axel Brandenburg, Yuan Li, Sasha Tchekhovskoy and Siyao Xu

Turbulence is ubiquitous and crucially affects diverse astrophysical processes, such as star and planet formation, cosmic ray acceleration and transport, cold gas formation in circumgalactic environments, dynamo amplification of magnetic fields, accretion, and magnetic reconnection. Direct measurements of astrophysical turbulence are challenging due to the limited sample sizes, resolution, projection effects, and coupling between different physical quantities.

On the theoretical side, advances in plasma and fluid dynamics simulations have characterized magnetized turbulence in great detail and achieved a new understanding of turbulence over a wide range of scales, both in idealized settings and realistic astrophysical contexts, ranging from the interior of stars, the Solar wind, accretion disks, relativistic jets and outflows, to gas in and around galaxies and galaxy clusters. On the observational side, it is now possible to probe the role turbulence plays in a wide range of astrophysical environments with unprecedented sample size and precision.

This program will take advantage of these advances and bring together experts in theory, computation, and observation from various sub-fields of astrophysics and plasma physics. Some of the topics to be discussed include:

  • How to extract the maximum insight into turbulence from the numerical simulations of different astrophysical environments?
  • How can we test theory and numerical simulations using observations of astrophysical turbulence?
  • What are the challenges facing different sub-fields, and what opportunities for cross-fertilization exist?
  • How to capitalize upon our growing understanding of turbulence to build better models of astrophysical systems?
  • How to incorporate turbulence into global models when global direct numerical simulations are prohibitive due to the vast scale separations?
  • What new insights into astrophysical turbulence can be obtained from ongoing and future missions and experiments?