Multiphase condensation in cluster halos: interplay of cooling, buoyancy and mixing

Abstract

Gas in the central regions of cool-core clusters and other massive halos has a short cooling time ($\lesssim 1\mathrm{Gyr}$). Theoretical models predict that this gas is susceptible to multiphase condensation, in which cold gas is expected to condense out of the hot phase if the ratio of the thermal instability growth time scale ($t_{\mathrm{ti}}$) to the free-fall time ($t_{\mathrm{ff}}$) is $t_{\mathrm{ti}}/t_{\mathrm{ff}}\lesssim 10$. The turbulent mixing time $t_{\mathrm{mix}}$ is another important time scale: if $t_{\mathrm{mix}}$ is short enough, the fluctuations are mixed before they can cool. In this study, we perform high-resolution ($512^2\times 768$--$1024^2\times 1536$ resolution elements) hydrodynamic simulations of turbulence in a stratified medium, including radiative cooling of the gas. We explore the parameter space of $t_{\mathrm{ti}}/t_{\mathrm{ff}}$ and $t_{\mathrm{ti}}/t_{\mathrm{mix}}$ relevant to galaxy and cluster halos. We also study the effect of the steepness of the entropy profile, the strength of turbulent forcing and the nature of turbulent forcing (natural mixture vs. compressive modes) on multiphase gas condensation. We find that larger values of $t_{\mathrm{ti}}/t_{\mathrm{ff}}$ or $t_{\mathrm{ti}}/t_{\mathrm{mix}}$ generally imply stability against multiphase gas condensation, whereas larger density fluctuations (e.g., due to compressible turbulence) promote multiphase gas condensation. We propose a new criterion $\min (t_{\mathrm{ti}}/\min (t_{\mathrm{mix}},t_{\mathrm{ff}}))\lesssim c_2\times \exp (c_1{\sigma }_s)$ for when the halo becomes multiphase, where ${\sigma }_s$ denotes the amplitude of logarithmic density fluctuations and $c_1\simeq 6$, $c_2\simeq 1.8$ from an empirical fit to our results.

arXiv commentMNRAS-accepted version, 16+2 (appendix) pages, 11 figures, simulation movies available at this playlist on youtube: https://youtube.com/playlist?list=PLuaNgQ1v_KMZlkKXdB7hcaQ7-hb0hmY7G

References in corpus (53)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Observational Evidence of AGN Feedback
• Comparing the statistics of interstellar turbulence in simulations and observations: Solenoidal versus compressive turbulence forcing
• Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters
• The Quiescent Intracluster Medium in the Core of the Perseus Cluster
• Density probability distribution in one-dimensional polytropic gas dynamics
• Thermal Instability in Gravitationally-Stratified Plasmas: Implications for Multi-Phase Structure in Clusters and Galaxy Halos
• Thermal Instability & the Feedback Regulation of Hot Halos in Clusters, Groups, and Galaxies
• CMasher: Scientific colormaps for making accessible, informative and 'cmashing' plots
• Numerical simulations of compressively driven interstellar turbulence: I. Isothermal gas
• A Global Model For Circumgalactic and Cluster-Core Precipitation
• Resolving small-scale cold circumgalactic gas in TNG50
• A robust numerical scheme for highly compressible magnetohydrodynamics: Nonlinear stability, implementation and tests
• Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and Clusters
• Extreme AGN feedback in the Massive Cluster Survey (MACS): a detailed study of X-ray cavities at z > 0.3
• Multiphase Gas and the Fractal Nature of Radiative Turbulent Mixing Layers
• Ubiquitous cold and massive filaments in cool core clusters
• Cool core cycles: Cold gas and AGN jet feedback in cluster cores
• Cooling Time, Freefall Time, and Precipitation in the Cores of ACCEPT Galaxy Clusters
• The Launching of Cold Clouds by Galaxy Outflows II: The Role of Thermal Conduction
• The density structure and star formation rate of non-isothermal polytropic turbulence
• Constraining turbulence and conduction in the hot ICM through density perturbations
• A new density variance - Mach number relation for subsonic and supersonic, isothermal turbulence
• The Impact of Cosmic Rays on Thermal Instability in the Circumgalactic Medium
• A Role for Turbulence in Circumgalactic Precipitation
• Constraining Gas Motions in the Intra-Cluster Medium
• Gas perturbations in cool cores of galaxy clusters: effective equation of state, velocity power spectra and turbulent heating
• The impact of magnetic fields on thermal instability
• Thermodynamic properties, multiphase gas and AGN feedback in a large sample of giant ellipticals
• The nature of filamentary cold gas in the core of the Virgo Cluster
• Turbulence and cooling in galaxy cluster cores
• The Circumgalactic Medium of Milky Way-like Galaxies in the TNG50 Simulation -- I: Halo Gas Properties and the Role of SMBH Feedback
• Multiphase gas in the circumgalactic medium: relative role of $t_{\mathrm{cool}}/t_{\mathrm{ff}}$ and density fluctuations
• Dense gas formation and destruction in a simulated Perseus-like galaxy cluster with spin-driven black hole feedback
• Cold gas in cluster cores: Global stability analysis and non-linear simulations of thermal instability
• Cosmic Rays or Turbulence can Suppress Cooling Flows (Where Thermal Heating or Momentum Injection Fail)
• Turbulent dynamo in the two-phase interstellar medium
• Turbulence in the intracluster medium: simulations, observables & thermodynamics
• Turbulent density and pressure fluctuations in the stratified intracluster medium
• Velocity structure functions in multiphase turbulence: interpreting kinematics of H$\alpha$ filaments in cool core clusters
• Turbulence in stratified atmospheres: implications for the intracluster medium
• Hitomi observations of Perseus support heating by mixing
• Thermal Instability of Halo Gas Heated by Streaming Cosmic Rays
• Non-Kolmogorov turbulence in multiphase intracluster medium driven by cold gas precipitation and AGN jets
• Shatter or not: role of temperature and metallicity in the evolution of thermal instability
• A Graphical Interpretation of Circumgalactic Precipitation
• Shattering and growth of cold clouds in galaxy clusters: the role of radiative cooling, magnetic fields and thermal conduction
• AGN feedback duty cycle in Planck SZ selected clusters using Chandra observations
• FUV line emission, gas kinematics, and discovery of [Fe XXI] $\lambda$1354.1 in the sightline towards a filament in M87
• Molecular gas along the old radio jets of the cluster-central type 2 quasar IRAS 09104+4109
• Circumnuclear Medium around the Central AGN in a Cool-Core Cluster, Abell 1644-South

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