Surprises in astrophysical gasdynamics
@article{Balbus2016SurprisesIA, title={Surprises in astrophysical gasdynamics}, author={Steven A. Balbus and William J Potter}, journal={Reports on Progress in Physics}, year={2016}, volume={79} }
Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one’s a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an…
8 Citations
ON HELIUM MIXING IN QUASI-GLOBAL SIMULATIONS OF THE INTRACLUSTER MEDIUM
- Physics
- 2016
The assumption of a spatially uniform helium distribution in the intracluster medium (ICM) can lead to biases in the estimates of key cluster parameters if composition gradients are present. The…
Dynamical Thermal Instability in Highly Supersonic Outflows
- PhysicsThe Astrophysical Journal
- 2022
Acceleration can change the ionization of X-ray irradiated gas to the point that the gas becomes thermally unstable. Cloud formation, the expected outcome of thermal instability (TI), will be…
The effect of rotation on the thermal instability of stratified galactic atmospheres – II. The formation of high-velocity clouds
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2019
Whether High Velocity Clouds (HVCs) can form by condensation of the hot ($T \sim 10^6 \, {\rm K}$) Galactic corona as a consequence of thermal instabilities has been controversial. Here we re-examine…
Singular diffusionless limits of double-diffusive instabilities in magnetohydrodynamics
- Mathematics, PhysicsProceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
- 2017
Stability analysis of amplitude transport equations of short-wavelength approximation finds that the threshold of the diffusionless AMRI via the Hamilton–Hopf bifurcation is a singular limit of the thresholds of the viscous and resistive AMRI corresponding to the dissipative Hopf b ifurcation and manifests itself as the Whitney umbrella singular point.
Exploring the physical properties of the cool circumgalactic medium with a semi-analytic model
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2019
We develop a semi-analytic model to explore the physical properties of cool pressure-confined circumgalactic clouds with mass ranging from $10$ to $10^{8} \, \rm M_{\odot}$ in a hot diffuse halo. We…
Braginskii viscosity on an unstructured, moving mesh accelerated with super-time-stepping
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2019
We present a method for efficiently modelling Braginskii viscosity on an unstructured, moving mesh. Braginskii viscosity, i.e. anisotropic transport of momentum with respect to the direction of the…
Short-wavelength local instabilities of a circular Couette flow with radial temperature gradient
- Physics, EngineeringJournal of Fluid Mechanics
- 2017
We perform a linearized local stability analysis for short-wavelength perturbations of a circular Couette flow with a radial temperature gradient. Axisymmetric and non-axisymmetric perturbations are…
The effect of rotation on the thermal instability of stratified galactic atmospheres – I. Local analysis
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2019
Observations show that (i) multiple gas phases can coexist in the atmospheres of galaxies and clusters; (ii) these atmospheres may be significantly rotating in the inner parts, with typical…
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