On the dynamics and survival of fractal clouds in galactic winds

  title={On the dynamics and survival of fractal clouds in galactic winds},
  author={W E Banda-Barrag{\'a}n and Federico Zertuche and Christoph Federrath and J Garc{\'i}a Del Valle and Marcus Br{\"u}ggen and Alexander Y. Wagner},
  journal={Monthly Notices of the Royal Astronomical Society},
Recent observations suggest that dense gas clouds can survive even in hot galactic winds. Here we show that the inclusion of turbulent densities with different statistical properties has significant effects on the evolution of wind-swept clouds. We investigate how the initial standard deviation of the lognormal density field influences the dynamics of quasi-isothermal clouds embedded in supersonic winds. We compare uniform, fractal solenoidal, and fractal compressive cloud models in both 3D… 

Figures and Tables from this paper

Shock–multicloud interactions in galactic outflows – II. Radiative fractal clouds and cold gas thermodynamics
Galactic winds are crucial to the cosmic cycle of matter, transporting material out of the dense regions of galaxies. Observations show the coexistence of different temperature phases in such
On the survival of cool clouds in the circumgalactic medium
We explore the survival of cool clouds in multiphase circumgalactic media. We revisit the ‘cloud-crushing problem’ in a large survey of simulations including radiative cooling, self-shielding,
The Launching of Cold Clouds by Galaxy Outflows. III. The Influence of Magnetic Fields
Motivated by observations of outflowing galaxies, we investigate the combined impact of magnetic fields and radiative cooling on the evolution of cold clouds embedded in a hot wind. We perform a
Synthetic Absorption Lines from Simulations of Multiphase Gas in Galactic Winds
Supernova-driven galactic winds are multiphase streams of gas that are often observed flowing at a range of velocities out of star-forming regions in galaxies. In this study, we use high-resolution
The in situ formation of molecular and warm ionized gas triggered by hot galactic outflows
Molecular outflows contributing to the matter cycle of star forming galaxies are now observed in small and large systems at low and high redshift. Their physical origin is still unclear. In most
Kinematics and Dynamics of Multiphase Outflows in Simulations of the Star-forming Galactic Interstellar Medium
Galactic outflows produced by stellar feedback are known to be multiphase in nature. Both observations and simulations indicate that the material within several kpc of galactic disk mid-planes
Shock–multicloud interactions in galactic outflows – I. Cloud layers with lognormal density distributions
We report three-dimensional hydrodynamical simulations of shocks (${\cal M_{\rm shock}}\geq 4$) interacting with fractal multicloud layers. The evolution of shock-multicloud systems consists of four
Multiphase AGN Winds from X-Ray-irradiated Disk Atmospheres
The mechanism of thermal driving for launching mass outflows is interconnected with classical thermal instability (TI). In a recent paper, we demonstrated that as a result of this interconnectedness,
Momentum and energy injection by a supernova remnant into an inhomogeneous medium
  • J. Pittard
  • Physics
    Monthly Notices of the Royal Astronomical Society
  • 2019
We investigate the effect of mass-loading from embedded clouds on the evolution of supernova remnants and on the energy and momentum that they inject into an inhomogeneous interstellar medium. We
A new model for including galactic winds in simulations of galaxy formation – I. Introducing the Physically Evolved Winds (PhEW) model
The propagation and evolution of cold galactic winds in galactic haloes is crucial to galaxy formation models. However, modelling of this process in hydrodynamic simulations of galaxy formation is


Starburst-Driven Galactic Winds: Filament Formation and Emission Processes
We have performed a series of three-dimensional simulations of the interaction of a supersonic wind with a nonspherical radiative cloud. These simulations are motivated by our recent
The Launching of Cold Clouds by Galaxy Outflows I: Hydrodynamic Interactions with Radiative Cooling
To better understand the nature of the multiphase material found in outflowing galaxies, we study the evolution of cold clouds embedded in flows of hot and fast material. Using a suite of
The dynamics and high-energy emission of conductive gas clouds in supernova-driven galactic superwinds
Superwinds from starburst galaxies are multiphase outflows that sweep up and incorporate ambient galactic disc and halo gas. The interaction of this denser material with the more diffuse hot wind gas
The Launching of Cold Clouds by Galaxy Outflows II: The Role of Thermal Conduction
We explore the impact of electron thermal conduction on the evolution of radiatively-cooled cold clouds embedded in flows of hot and fast material, as occur in outflowing galaxies. Performing a
Magnetized gas clouds can survive acceleration by a hot wind
We present three-dimensional magnetohydrodynamic simulations of magnetized gas clouds accelerated by hot winds. We initialize gas clouds with tangled internal magnetic fields and show that this field
Filament formation in wind–cloud interactions– II. Clouds with turbulent density, velocity, and magnetic fields
We present a set of numerical experiments designed to systematically investigate how turbulence and magnetic fields influence the morphology, energetics, and dynamics of filaments produced in
Filament formation in wind–cloud interactions – I. Spherical clouds in uniform magnetic fields
Filamentary structures are ubiquitous in the interstellar medium, yet their formation, internal structure, and longevity have not been studied in detail. We report the results from a comprehensive
The physics of multiphase gas flows: fragmentation of a radiatively cooling gas cloud in a hot wind
Galactic winds exhibit a multiphase structure that consists of hot-diffuse and cold-dense phases. Here we present high-resolution idealised simulations of the interaction of a hot supersonic wind
We present hydrodynamic simulations of high-velocity clouds (HVCs) traveling through the hot, tenuous medium in the Galactic halo. A suite of models was created using the FLASH hydrodynamics code,
Shock-triggered formation of magnetically-dominated clouds
Aims. Our aim is to understand the formation of a magnetically dominated molecular cloud out of an atomic cloud. Methods. A thermally stable warm atomic cloud is initially in static equilibrium with