相关论文: Plasma Instabilities in the Context of Current Hel…
The assumption of a spatially uniform helium distribution in the intracluster medium can lead to biases in the estimates of key cluster parameters if composition gradients are present. The helium concentration profile in galaxy clusters is…
The distribution of Helium in the intracluster medium (ICM) permeating galaxy clusters is not well constrained due to the very high plasma temperature. Therefore, the plasma is often assumed to be homogeneous. A non-uniform Helium…
Over the last decade, substantial efforts have been devoted to understanding the stability properties, transport phenomena, and long-term evolution of weakly-collisional, magnetized plasmas which are stratified in temperature. These studies…
In this paper we investigate how convective instabilities influence heat conduction in the intracluster medium (ICM) of cool-core galaxy clusters. The ICM is a high-beta, weakly collisional plasma in which the transport of momentum and heat…
Clusters of galaxies are embedded in halos of optically thin, gravitationally stratified, weakly magnetized plasma at the system's virial temperature. Due to radiative cooling and anisotropic heat conduction, such intracluster medium (ICM)…
In galaxy clusters, the hot intracluster medium (ICM) can develop a striking multi-phase structure around the brightest cluster galaxy. Much work has been done on understanding the origin of this central nebula, but less work has studied…
We discuss how helium sedimentation in galaxy clusters can affect the history of star formation in the central cluster galaxy. As helium sediments, the gas density in the inner regions of the cluster increases and there is also a…
Recent theoretical studies predict that the inner regions of galaxy clusters may have an enhanced helium abundance due to sedimentation over the cluster lifetime. If sedimentation is not suppressed (e.g., by tangled magnetic fields), this…
We analyze the linear stability of a dilute, hot plasma, taking into account the effects of stratification and anisotropic thermal conduction. The work is motivated by attempts to understand the dynamics of the intracluster medium in galaxy…
The intracluster medium of galaxy clusters is a weakly collisional, high-beta plasma in which the transport of heat and momentum occurs primarily along magnetic-field lines. Anisotropic heat conduction allows convective instabilities to be…
In this Letter, we consider the role played by the sedimentation of helium nuclei on the emissivity and metallicity distribution of the X-ray emitting plasma in the cores of relaxed galaxy clusters. We model the gas density and temperature…
Observations of the cores of nearby galaxy clusters show H$\alpha$ and molecular emission line filaments. We argue that these are the result of {\em local} thermal instability in a {\em globally} stable galaxy cluster core. We present…
(abridged) The ICM has been suggested to be buoyantly unstable in the presence of magnetic field and anisotropic thermal conduction. We perform first cosmological simulations of galaxy cluster formation that simultaneously include magnetic…
The distribution of metals and temperature in the intracluster medium (ICM) provides key insights into galaxy cluster evolution, revealing information about chemical enrichment and heating and cooling processes, respectively. To access this…
A long-standing question is whether radiative cooling can lead to local condensations of cold gas in the hot atmospheres of galaxies and galaxy clusters. We address this problem by studying the nature of local instabilities in rotating,…
We consider the role of diffusion in the redistribution of elements in the hot interstellar medium (ISM) of early-type galaxies. It is well known that gravitational sedimentation can affect significantly the abundances of helium and heavy…
We examine the long-standing cooling flow problem in galaxy clusters with 3D MHD simulations of isolated clusters including radiative cooling and anisotropic thermal conduction along magnetic field lines. The central regions of the…
We analyze the stability of a dilute plasma with thermal and composition gradients in the limit where conduction is slow compared to the dynamical timescale. We find necessary and sufficient conditions for stability when the background…
We model the intracluster medium as a weakly collisional plasma that is a binary mixture of the hydrogen and the helium ions, along with free electrons. When, owing to the helium sedimentation, the gradient of the mean molecular weight (or…
In weakly-collisional plasmas such as the intracluster medium (ICM), heat and momentum transport become anisotropic with respect to the local magnetic field direction. Anisotropic heat conduction causes the slow magnetosonic wave to become…