Related papers: Instabilities in Photoionized Interstellar Gas
We have developed a new formalism to compute the thermodynamic coefficient Gamma1 in the theory of stellar and atmospheric stability. We generalize the classical derivation of the first adiabatic index, which is based on the assumption of…
The temperature of the low-density intergalactic medium is set by the balance between adiabatic cooling resulting from the expansion of the universe, and photo-heating by the UV-background. We have analysed the Lyman-alpha forest of eleven…
It is generally recognized that the interstellar medium has a vast range of densities and temperatures. While these two properties are usually anticorrelated with each other, there are nevertheless variations in their product, i.e., the…
The dynamics of linear perturbations in a radiatively cooling dusty plasma is considered, with the charge of both dust ($Z_d$) and plasma ($Z_p$) components being allowed to vary with their densities. It is shown that in the long-wavelength…
Context: Compensated-current systems are established in response to hot ion beams in terrestrial foreshock regions, around supernova remnants, and in other space and astrophysical plasmas. Aims: We study a non-resonant reactive instability…
We show that, under Braginskii magneto-hydrodynamics, anti-parallel gradients in average ion charge state and electron temperature can be unstable to the growth of self-generated magnetic fields. The instability is analogous to the…
We study the problem of time-dependent photoionization of low density gaseous nebulae subjected to sudden changes in the intensity of ionizing radiation. To this end, we write a computer code that solves the full time-dependent energy…
Aims. The main objective of this article is to provide a simple physical framework with permits a quantitative comparison of measurements of the temperature fluctuations in the ionized interstellar medium with possible mechanisms which can…
We consider the evolution of the ionization zone around Population III stars with $M_*\sim 25-200 M_\odot$ in protogalaxies with $M\sim 10^7 M_\odot$ at redshifts $z = 12$, assuming that the dark matter profile is a modified isothermal…
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 velocities that approach or even exceed the local…
In this work, we have carried out a two-dimensional (2D) simulation of thermal instability (TI) in interstellar matter (ISM), considering it to be a weakly ionised inviscid plasma with radiation loss. We carry out the simulation using our…
Context: The thermal instability is one of the dynamical agents for turbulence in the diffuse interstellar medium, where both, turbulence and thermal instability interact in a highly non-linear manner. Aims: We study basic properties of…
We report on a first-principles numerical study of magnetic reconnection in plasmas with different initial ion-to-electron temperature ratios. In cases where this ratio is significantly below unity, we observe intense wave activity in the…
Thermal instability (TI) plays a crucial role in the formation of multiphase structures and their dynamics in the Interstellar Medium (ISM) and is a leading theory for cold cloud creation in various astrophysical environments. In this paper…
The ionization state of the gas plays a key role in the MHD of protoplanetary disks. However, the ionization state can depend on the gas dynamics, because electric fields induced by MHD turbulence can heat up plasmas and thereby affect the…
Photoionized gases are prevalent throughout the universe. In such gases, the ion concentration typically exhibits two response modes to radiation: a positive response in the low-ionization state and a negative response in the…
We examine the thermodynamic state and cooling of the low-$z$ Circum-Galactic Medium (CGM) in five FIRE-2 galaxy formation simulations of Milky Way-mass galaxies. We find that the CGM in these simulations is generally multiphase and…
We develop an unconditionally stable numerical method for solving the coupling between two fluids (frictional forces/heatings, ionization, and recombination), and investigate the dynamical condensation process of thermally unstable gas that…
An overview is presented of the main properties of the interstellar medium. Evidence is summarized that the interstellar medium is highly turbulent, driven on different length scales by various energetic processes. Large-scale turbulence…
The atmospheres of hot Jupiters and other strongly-forced exoplanets are susceptible to a thermal instability in the presence of ohmic dissipation, weak magnetic drag and strong winds. The instability occurs in radiatively-dominated…