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Related papers: Solenoidal versus compressive turbulence forcing

200 papers

We present numerical studies of compressible, decaying turbulence, with and without magnetic fields, with initial rms Alfven and Mach numbers ranging up to five, and apply the results to the question of the support of star-forming…

Astrophysics · Physics 2009-10-30 Mordecai-Mark Mac Low , Ralf S. Klessen , Andreas Burkert , Michael D. Smith

The fragmentation of molecular clouds (MC) into protostellar cores is a central aspect of the process of star formation. Because of the turbulent nature of super-sonic motions in MCs, it has been suggested that dense structures such as…

Astrophysics · Physics 2009-10-31 Paolo Padoan , Mika Juvela , Alyssa A. Goodman , AAke Nordlund

[Abridged] Theoretical and numerical studies of star formation have shown that magnetic field (B) has a strong influence on both disk formation and fragmentation; even a relatively low B can prevent these processes. However, very few…

Solar and Stellar Astrophysics · Physics 2015-06-12 Marc Joos , Patrick Hennebelle , Andrea Ciardi , Sebastien Fromang

Motivated by the observed differences in the nebular emission of nearby and high-redshift galaxies, we carry out a set of direct numerical simulations of turbulent astrophysical media exposed to a UV background. The simulations assume a…

Astrophysics of Galaxies · Physics 2017-11-15 William J. Gray , Evan Scannapieco

Coagulation driven by supersonic turbulence is primarily an astrophysical problem because coagulation processes on Earth are normally associated with incompressible fluid flows at low Mach numbers, while dust aggregation in the interstellar…

Fluid Dynamics · Physics 2021-04-30 Xiang-Yu Li , Lars Mattsson

Stars form from dense cores in turbulent molecular clouds. According to the standard scenario of star formation, dense cores are created by cloud fragmentation. However, the physical mechanisms driving this process are still not fully…

Astrophysics of Galaxies · Physics 2025-03-11 Kousuke Ishihara , Fumitaka Nakamura , Patricio Sanhueza , Masao Saito

Density fluctuations produced by supersonic turbulence are of great importance to astrophysical chemical models. A property of these density fluctuations is that the two point correlation function decreases with increasing scale separation.…

Astrophysics of Galaxies · Physics 2020-09-22 Shmuel Bialy , Blakesley Burkhart

Turbulence plays a crucial role in shaping the structure of the interstellar medium. The ratio of the three-dimensional density contrast ($\sigma_{\rho/\rho_0}$) to the turbulent sonic Mach number ($\mathcal{M}$) of an isothermal,…

Incompressible Magnetohydrodynamics is often assumed to describe solar wind turbulence. We use extended self similarity to reveal scaling in structure functions of density fluctuations in the solar wind. Obtained scaling is then compared…

Astrophysics · Physics 2009-11-10 Bogdan Hnat , Sandra C. Chapman , George Rowlands

We describe an overall picture of galactic-scale star formation. Recent high-resolution magneto-hydrodynamical simulations of two-fluid dynamics with cooling/heating and thermal conduction have shown that the formation of molecular clouds…

Astrophysics of Galaxies · Physics 2015-07-29 Shu-ichiro Inutsuka , Tsuyoshi Inoue , Kazunari Iwasaki , Takashi Hosokawa

We test the sensitivity of hydrodynamic and magnetohydrodynamic turbulent convection simulations with respect to Mach number, thermal and magnetic boundary conditions, and the centrifugal force. We find that varying the luminosity, which…

Solar and Stellar Astrophysics · Physics 2019-12-16 Petri J. Käpylä , Frederick A. Gent , Nigul Olspert , Maarit J. Käpylä , Axel Brandenburg

We employ the IllustrisTNG simulation data to investigate the turbulent and thermal motions of the cosmic baryonic fluid. With continuous wavelet transform techniques, we define the pressure spectra, or density-weighted velocity power…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-12 Yun Wang , Ping He

We investigated incompressible and compressible magnetohydrodynamic (MHD) energy cascade rates in the solar wind at different heliocentric distances. We used in situ magnetic field and plasma observations provided by the Parker Solar Probe…

Solar and Stellar Astrophysics · Physics 2023-11-23 Maia Brodiano , Pablo Dmitruk , Nahuel Andrés

The discovery that axisymmetric dust rings are ubiquitous in protoplanetary disks has provoked a flurry of research on the role of pressure bumps in planet formation. High-resolution simulations by our group have shown that even a modest…

Earth and Planetary Astrophysics · Physics 2022-03-14 Daniel Carrera , Andrew Thomas , Jacob B. Simon , Matthew A. Small , Katherine A. Kretke , Hubert Klahr

We discuss star formation in the turbulent interstellar medium. We argue that morphological appearance and dynamical evolution of the gas is primarily determined by supersonic turbulence, and that stars form via a process we call…

Astrophysics · Physics 2007-05-23 Ralf S. Klessen , Javier Ballesteros-Paredes

We use a suite of cosmological hydrodynamic simulations, run by two fixed grid codes, to investigate the properties of solenoidal and dilatational motions of the intergalactic medium (IGM), and the impact of numerical viscosity on…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-23 Weishan Zhu , Long-Long Feng , Yinhua Xia , Chi-Wang Shu , Qiu-Sheng Gu , Li-Zhi Fang

We identify forcing mechanisms that separately amplify subsonic and supersonic features obtained from a linearized Navier-Stokes based model for compressible parallel boundary layers. Resolvent analysis is used to analyse the linear model,…

Fluid Dynamics · Physics 2025-01-29 Anagha Madhusudanan , Gregory Stroot , Beverley J. McKeon

Whilst the star formation rate (SFR) of molecular clouds and galaxies is key in understanding galaxy evolution, the physical processes which determine the SFR remain unclear. This uncertainty about the underlying physics has resulted in…

Astrophysics of Galaxies · Physics 2015-05-14 Diane M. Salim , Christoph Federrath , Lisa J. Kewley

Motivated by its importance for modeling dust particle growth in protoplanetary disks, we study turbulence-induced collision statistics of inertial particles as a function of the particle friction time, tau_p. We show that turbulent…

Earth and Planetary Astrophysics · Physics 2015-06-23 Liubin Pan , Paolo Padoan

(abridged) Context: Turbulent diffusion of large-scale flows and magnetic fields play major roles in many astrophysical systems. Aims: Our goal is to compute turbulent viscosity and magnetic diffusivity, relevant for diffusing large-scale…

Solar and Stellar Astrophysics · Physics 2020-04-29 Petri J. Käpylä , Matthias Rheinhardt , Axel Brandenburg , Maarit J. Käpylä
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