相关论文: Heating and Turbulence Driving by Galaxy Motions i…
We use recent X-ray observations of the intracluster medium (ICM) of the galaxy group NGC 5813 to confront theoretical studies of ICM thermal evolution with the newly derived ICM properties. We argue that the ICM of the cooling flow galaxy…
Observations of galaxy clusters show that the intracluster medium (ICM) is likely to be turbulent and is certainly magnetized. The properties of this magnetized turbulence are determined both by fundamental nonlinear magnetohydrodynamic…
Heat input roughly balances radiative cooling in the gaseous cores of galaxy clusters even when the central cooling time is short, implying that cooling triggers a feedback loop that maintains thermal balance. Furthermore, cores with short…
Simulations suggest that turbulence is ubiquitous in the circumgalactic medium (CGM), though the source and properties of CGM turbulence is uncertain. Using analytic considerations and hydrodynamic simulations we study how CGM turbulence is…
Clusters of galaxies form through major merger and/or absorption of smaller groups. In fact, some characteristic structures such as cold fronts, which are likely relevant to moving substructures, are found by {\it Chandra}. It is expected…
Simulations of galaxy clusters have a difficult time reproducing the radial gas-property gradients and red central galaxies observed to exist in the cores of galaxy clusters. Thermal conduction has been suggested as a mechanism that can…
We present self-consistent cosmological magnetohydrodynamic (MHD) simulations that simultaneously follow the formation of a galaxy cluster and the magnetic field ejection by an active galactic nucleus (AGN). We find that the magnetic fields…
In the intracluster medium (ICM) of galaxies, exchanges of heat across magnetic field lines are strongly suppressed. This anisotropic heat conduction, in the presence of a large-scale temperature gradient, destabilizes the outskirts of…
The hot intracluster medium (ICM) provides a unique laboratory to test multi-scale physics in numerical simulations and probe plasma physics. Utilizing archival Chandra observations, we measure density fluctuations in the ICM in a sample of…
It is now widely accepted that heating processes play a fundamental role in galaxy clusters, struggling in an intricate but fascinating `dance' with its antagonist, radiative cooling. Last generation observations, especially X-ray, are…
Galaxy clusters host a large reservoir of diffuse plasma with radially-varying temperature profiles. The efficiency of thermal conduction in the intracluster medium (ICM) is complicated by the existence of turbulence and magnetic fields,…
(Abridged) Existing models invoking AGN activty to resolve the cooling flow conundrum in galaxy clusters focus exclusively on the role of the central galaxy. Such models require fine-tuning of highly uncertain microscopic transport…
We conduct two-dimensional hydrodynamical simulations of jets expanding in the intra-cluster medium (ICM). We find that for a fat, i.e. more or less spherical, bubble attached to the center to be formed the jet should have high momentum…
Interstellar medium (ISM) structures gravitationally perturb stellar orbits in galactic disks, driving orbital heating and migration. However, studies of these transport processes tend to model the ISM very crudely, e.g., as a collection of…
Determining the origin of turbulence in galaxy clusters, and quantifying its transport of heat, is an outstanding problem, with implications for our understanding of their thermodynamic history and structure. As the dilute plasma of the…
Galactic disks consist of both stars and gas. The gas is more dynamically responsive than the stars, and strongly nonlinear structures and velocities can develop in the ISM even while stellar surface density perturbations remain…
We investigate the properties of the intracluster medium (ICM) that forms within N-body/hydrodynamical simulations of galaxy clusters in a \LambdaCDM cosmology. When radiative cooling and a simple model for galactic feedback are included,…
Feedback from active galactic nuclei (AGN) is believed to play a significant role in suppressing cooling flows in cool-core (CC) clusters. Turbulence in the intracluster medium (ICM), which may be induced by AGN activity or pre-existing…
We review the general properties of the intracluster medium (ICM) in clusters that host a cooling flow, and in particular the effects on the ICM of the injection of hot plasma by a powerful active galactic nucleus (AGN). It is observed…
Turbulent heating may play an important role in galaxy-cluster plasmas, but if turbulent heating is to balance radiative cooling in a quasi-steady state, some mechanism must set the turbulent velocity to the required value. This paper…