Modelling supernova-driven turbulence

Gent, Frederick A.; Low, Mordecai–Mark Mac; Käpylä, Maarit J.; Sarson, Graeme R.; Hollins, James F.

doi:10.1080/03091929.2019.1634705

Cited by 16 publications

(22 citation statements)

References 39 publications

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“…We solve the system of nonideal, compressible, nonisothermal MHD equations r r z r 2 are applied to all ISM models and resolve shock discontinuities with artificial diffusion of mass, momentum, and energy proportional to shock strength (see Gent et al 2020 for details). Equations (2) and (3) include terms with z D to provide momentum and energy conserving corrections for the artificial mass diffusion applying in Equation (1).…”

Section: Supernova-driven Turbulence Model Designmentioning

confidence: 99%

“…Unlike past experiments (Gent et al 2013a(Gent et al , 2013b(Gent et al , 2020, thermal diffusivity χ is also omitted, as the artificial diffusivities chosen are adequate to ensure numerical stability. The physical effects of thermal conductivity can be expected to be relevant only at the unresolved or marginally resolved Field length defined by Begelman & McKee (1990, named after George Field, not the magnetic field).…”

Section: Supernova-driven Turbulence Model Designmentioning

confidence: 99%

“…The physical effects of thermal conductivity can be expected to be relevant only at the unresolved or marginally resolved Field length defined by Begelman & McKee (1990, named after George Field, not the magnetic field). Terms containing n c , thermal energy, except in dense regions, where a proportion (<5%) may be kinetic E kin (see Gent et al 2020). Models with common s  have the same timing and location of explosions.…”

Section: Supernova-driven Turbulence Model Designmentioning

confidence: 99%

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Small-scale Dynamo in Supernova-driven Interstellar Turbulence

Gent

Low

Käpylä

et al. 2021

ApJL

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Magnetic fields grow quickly even at early cosmological times, suggesting the action of a small-scale dynamo (SSD) in the interstellar medium of galaxies. Many studies have focused on idealized turbulent driving of the SSD. Here we simulate more realistic supernova-driven turbulence to determine whether it can drive an SSD. Magnetic field growth occurring in our models appears inconsistent with simple tangling of magnetic fields, but consistent with SSD action, reproducing and confirming models by Balsara et al. that did not include physical resistivity η. We vary η, as well as the numerical resolution and supernova rate, , to delineate the regime in which an SSD occurs. For a given we find convergence for SSD growth rate with resolution of a parsec. For , with the solar neighborhood rate, the critical resistivity below which an SSD occurs is , and this increases with the supernova rate. Across the modeled range of 0.5–4 pc resolution we find that for , the SSD saturates at about 5% of kinetic energy equipartition, independent of growth rate. In the range growth rate increases with . SSDs in the supernova-driven interstellar medium commonly exhibit erratic growth.

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Section: Supernova-driven Turbulence Model Designmentioning

confidence: 99%

Section: Supernova-driven Turbulence Model Designmentioning

confidence: 99%

Section: Supernova-driven Turbulence Model Designmentioning

confidence: 99%

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Small-scale Dynamo in Supernova-driven Interstellar Turbulence

Gent

Low

Käpylä

et al. 2021

ApJL

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“…We stabilise the scheme by sixth-order hyper-diffusion with a fixed Reynolds number, which damps numerical noise near the Nyquist frequency while obtaining high fidelity over a large dynamical range (Yang & Krumholz 2012). Shocks are captured via artificial diffusion in every dynamical variable, and a correction term to the momentum equation is applied so that the total momentum is better conserved (Gent et al 2019). To relieve the Courant condition imposed by the background Keplerian shear velocity at large radial distances from the origin of the local shearing sheet, we use a sixth-order B-spline interpolation to integrate the shear advection terms (Yang, Johansen & Carrera 2017;Yang, Mac Low & Johansen 2018).…”

Section: Methodsmentioning

confidence: 99%

Morphological signatures induced by dust back reaction in discs with an embedded planet

Yang

Zhu

2019

Monthly Notices of the Royal Astronomical Society

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Recent observations have revealed a gallery of substructures in the dust component of nearby protoplanetary discs, including rings, gaps, spiral arms, and lopsided concentrations. One interpretation of these substructures is the existence of embedded planets. Not until recently, however, most of the modelling effort to interpret these observations ignored the dust back reaction to the gas. In this work, we conduct localshearing-sheet simulations for an isothermal, inviscid, non-self-gravitating, razor-thin dusty disc with a planet on a fixed circular orbit. We systematically examine the parameter space spanned by planet mass (0.1M th ≤ M p ≤ 1M th , where M th is the thermal mass), dimensionless stopping time (10 −3 ≤ τ s ≤ 1), and solid abundance (0 < Z ≤ 1). We find that when the dust particles are tightly coupled to the gas (τ s < 0.1), the spiral arms are less open and the gap driven by the planet becomes deeper with increasing Z, consistent with a reduced speed of sound in the approximation of a single dust-gas mixture. By contrast, when the dust particles are marginally coupled (0.1 τ s 1), the spiral structure is insensitive to Z and the gap structure in the gas can become significantly skewed and unidentifiable. When the latter occurs, the pressure maximum radially outside of the planet is weakened or even extinguished, and hence dust filtration by a low-mass (M p < M th ) planet could be reduced or eliminated. Finally, we find that the gap edges where the dust particles are accumulated as well as the lopsided large-scale vortices driven by a massive planet, if any, are unstable, and they are broken into numerous small-scale dust-gas vortices.

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“…The numerical handling of shocks with artificial viscosity is a main topic of the paper by Gent et al (2020). In addition to presenting several one-dimensional Riemann shock tube problems, the authors also show the detailed analysis of the evolution of individual three-dimensional supernova remnants.…”

Section: Introductionmentioning

confidence: 99%