Compressible turbulence in the interstellar medium: New insights from a high-resolution supersonic turbulence simulation

Abstract

The role of supersonic turbulence in structuring the interstellar medium (ISM) remains an unsettled question. Here, this problem is investigated using a newexact law of compressible isothermal hydrodynamic turbulence, which involves two-point correlations in physical space. The new law is shown to have a compact expression that contains a single flux term reminiscent of the incompressible case and a source term with a simple expression whose sign is given by the divergence of the velocity. The law is then used to investigate the properties of such a turbulence at integral Mach number $4$ produced by a massive numerical simulation with a grid resolution of $10,048^3$ points. The flux (resp. source) term was found to have positive (resp. negative) contribution to the total energy cascade rate, which is interpreted as a direct cascade amplified by compression, while their sum is constant in the inertial range. Using a local (in space) analysis it is shown that the source is mainly driven by filamentary structures in which the flux is negligible. Taking positive defined correlations reveals the existence of different turbulent regimes separated by the sonic scale, which determines the scale over which the non-negligible source modifies the scaling of the flux. Our study provides new insight into the dynamics and structures of supersonic interstellar turbulence.

arXiv comment8 pages, 6 Figures

References in corpus (40)

• Theory of Star Formation
• Control of star formation by supersonic turbulence
• Interstellar Turbulence I: Observations and Processes
• Comparing the statistics of interstellar turbulence in simulations and observations: Solenoidal versus compressive turbulence forcing
• Characterizing interstellar filaments with Herschel in IC5146
• The Star Formation Rate of Turbulent Magnetized Clouds: Comparing Theory, Simulations, and Observations
• The Statistics of Supersonic Isothermal Turbulence
• The Universality of Turbulence in Galactic Molecular Clouds
• Density probability distribution in one-dimensional polytropic gas dynamics
• Turbulent molecular clouds
• Observation of inertial energy cascade in interplanetary space plasma
• On the universality of supersonic turbulence
• The Fractal Density Structure in Supersonic Isothermal Turbulence: Solenoidal versus Compressive Energy Injection
• The link between turbulence, magnetic fields, filaments, and star formation in the Central Molecular Zone cloud G0.253+0.016
• On the universality of interstellar filaments: theory meets simulations and observations
• Exact relation for correlation functions in compressible isothermal turbulence
• Compressible Turbulence: The Cascade and its Locality
• Exact Relation with Two-point Correlation Functions and Phenomenological Approach for Compressible Magnetohydrodynamic Turbulence
• Is the Scaling of Supersonic Turbulence Universal?
• On the von Karman-Howarth equations for Hall MHD flows
• Compressible magnetohydrodynamic turbulence in the Earth's magnetosheath: estimation of the energy cascade rate using in situ spacecraft data
• Turbulence and star formation efficiency in molecular clouds: solenoidal versus compressive motions in Orion B
• Energy Cascade Rate In Compressible Fast And Slow Solar Wind Turbulence
• The conservative cascade of kinetic energy in compressible turbulence
• Statistical Description of Acoustic Turbulence
• Energy cascade and scaling in supersonic isothermal turbulence
• Energy cascade rate measured in a collisionless space plasma with MMS data and compressible Hall magnetohydrodynamic turbulence theory
• Von Karman-Howarth equation for Hall magnetohydrodynamics: Hybrid simulations
• Scaling of compressible magnetohydrodynamic turbulence in the fast solar wind
• Exact law for homogeneous compressible Hall magnetohydrodynamics turbulence
• Alternative derivation of exact law for compressible and isothermal magnetohydrodynamics turbulence
• On exact laws in incompressible Hall magnetohydrodynamic turbulence
• Energy cascade rate in isothermal compressible magnetohydrodynamic turbulence
• A Universal Law for Solar-Wind Turbulence at Electron Scales
• The effect of ambipolar diffusion on low-density molecular ISM filaments
• Energy transfer in compressible magnetohydrodynamic turbulence for isothermal self-gravitating fluids
• Exact relations for energy transfer in self-gravitating isothermal turbulence
• Examination of the four-fifths law for longitudinal third-order moments in incompressible magnetohydrodynamic turbulence in a periodic box
• A note on acoustic turbulence
• An exact result in strong wave turbulence of thin elastic plates

Cited by in corpus (18)

• Standard Self-Confinement and Extrinsic Turbulence Models for Cosmic Ray Transport are Fundamentally Incompatible with Observations
• The evolution of compressible solar wind turbulence in the inner heliosphere: PSP, THEMIS and MAVEN observations
• General exact law of compressible isentropic magnetohydrodynamic flows: theory and spacecraft observations in the solar wind
• A Statistical Study of the Compressible Energy Cascade Rate in Solar Wind Turbulence: Parker Solar Probe Observations
• Nature of Striation in 21 cm Channel Maps: Velocity Caustics
• The spectrum of magnetized turbulence in the interstellar medium
• Exact law for compressible pressure-anisotropic magnetohydrodynamic turbulence: toward linking energy cascade and instabilities
• Scale dependence and cross-scale transfer of kinetic energy in compressible hydrodynamic turbulence at moderate Reynolds numbers
• An in-depth numerical study of exact laws for compressible Hall magnetohydrodynamic turbulence
• Energy transfer, discontinuities and heating in the inner solar wind measured with a weak and local formulation of the Politano-Pouquet law
• Proof of the zeroth law of turbulence in one-dimensional compressible magnetohydrodynamics and shock heating
• Scale-by-scale kinetic energy budgets in multiphase turbulence
• Structure of iso-density sets in supersonic isothermal turbulence
• Taking control of compressible modes: bulk viscosity and the turbulent dynamo
• Impact of pressure anisotropy on the cascade rate of Hall-MHD turbulence with biadiabatic ions
• The contribution of dilatational motion to energy flux in homogeneous compressible turbulence
• Cascade of circulicity in compressible turbulence
• Diagnosing Turbulence in the Neutral and Molecular Interstellar Medium of Galaxies