Analytic growth rate of gravitational instability in self-gravitating planar polytropes

@article{Durrive2018AnalyticGR,
  title={Analytic growth rate of gravitational instability in self-gravitating planar polytropes},
  author={Jean-Baptiste Durrive and Mathieu Langer},
  journal={Journal of Fluid Mechanics},
  year={2018},
  volume={859},
  pages={362 - 399}
}
Gravitational instability is a key process that may lead to fragmentation of gaseous structures (sheets, filaments, haloes) in astrophysics and cosmology. We introduce here a method to derive analytic expressions for the growth rate of gravitational instability in a plane stratified medium. First, the main strength of our approach is to reduce this intrinsically fourth-order eigenvalue problem to a sequence of second-order problems. Second, an interesting by-product is that the unstable part of… 

Analyzing the instability dynamics of spherical complex astroclouds in a magnetized meanfluidic fabric

A generalized magnetohydrodynamic meanfluidic model is theoretically constructed to analyze the gravitational (Jeans) instability dynamics excitable in a spherical complex astrocloud on the

Gravitational instability of non-isothermal filamentary molecular clouds in presence of external pressure

Filamentary molecular clouds are omnipresent in the cold interstellar medium. Observational evidences show that the non-isothermal equations of state describe the filaments properties better than the

References

SHOWING 1-10 OF 81 REFERENCES

Oscillations and stability of polytropic filaments

We study the oscillations and stability of self-gravitating cylindrically symmetric fluid systems and collisionless systems. This is done by studying small perturbations to the equilibrium system and

The Gravitational Stability of a Compressed Slab of Gas

We consider the linear stability of an isothermal, pressure-bounded, self-gravitating gas slab. Such a configuration is unstable at sufficiently long wavelengths and grows at rate ∼ √Gρ, where ρ is

GRAVITATIONAL INSTABILITY OF ROTATING, PRESSURE-CONFINED, POLYTROPIC GAS DISKS WITH VERTICAL STRATIFICATION

We investigate the gravitational instability (GI) of rotating, vertically stratified, pressure-confined, polytropic gas disks using a linear stability analysis as well as analytic approximations. The

Collapse and Fragmentation in Finite Sheets

We present two-dimensional simulations of finite, self-gravitating gaseous sheets. Unlike the case of infinite sheets, such configurations do not constitute equilibrium states but instead are subject

Gravitational fragmentation in expanding shells

We investigate the gravitational fragmentation in expanding shells by applying an instability ‘thermometer’ similar to the Toomre parameter for instabilities in self-gravitating disks. For Sedov-like

Gravitational instability in a primordial collapsing gas cloud

This paper presents an analysis of the linear evolution of short-wavelength perturbations in a background fluid flow which is undergoing gravitational collapse on large scales. Local evolution

Axisymmetric modes in vertically stratified self-gravitating discs

We carry out a linear analysis of the vertical normal modes of axisymmetric perturbations in stratified, compressible, self-gravitating gaseous discs in the shearing-box approximation. An unperturbed

Linear stability of ideal MHD configurations. II. Results for stationary equilibrium configurations

In this paper, we continue exploring the consequences of the general equation of motion (EOM) governing all Lagrangian perturbations ξ about a time-dependent, ideal magnetohydrodynamic (MHD)

The fragmentation of expanding shells – II. Thickness matters

We study analytically the development of gravitational instability in an expanding shell having finite thickness. We consider three models for the radial density profile of the shell: (i) an analytic

CORE AND FILAMENT FORMATION IN MAGNETIZED, SELF-GRAVITATING ISOTHERMAL LAYERS

We examine the role of the gravitational instability in an isothermal, self-gravitating layer threaded by magnetic fields on the formation of filaments and dense cores. Using a numerical simulation,
...