Cloud properties across spatial scales in simulations of the interstellar medium

Abstract

Molecular clouds (MC) are structures of dense gas in the interstellar medium (ISM), that extend from ten to a few hundred parsecs and form the main gas reservoir available for star formation. Hydrodynamical simulations of varying complexity are a promising way to investigate MC evolution and their properties. However, each simulation typically has a limited range in resolution and different cloud extraction algorithms are used, which complicates the comparison between simulations. In this work, we aim to extract clouds from different simulations covering a wide range of spatial scales. We compare their properties, such as size, shape, mass, internal velocity dispersion and virial state. We apply the Hop cloud detection algorithm on (M)HD numerical simulations of stratified ISM boxes and isolated galactic disk simulations that were produced using Flash Ramses and Arepo We find that the extracted clouds are complex in shape ranging from round objects to complex filamentary networks in all setups. Despite the wide range of scales, resolution, and sub-grid physics, we observe surprisingly robust trends in the investigated metrics. The mass spectrum matches in the overlap between simulations without rescaling and with a high-mass slope of $\mathrm{d}N/\mathrm{d}\ln M\propto -1$ in accordance with theoretical predictions. The internal velocity dispersion scales with the size of the cloud as $\sigma \propto R^{0.75}$ for large clouds ($R\gtrsim 3\mathrm{pc}$). For small clouds we find larger sigma compared to the power-law scaling, as seen in observations, which is due to supernova-driven turbulence. Almost all clouds are gravitationally unbound with the virial parameter scaling as ${\alpha }_{\mathrm{vir}}\propto M^{-0.4}$, which is slightly flatter compared to observed scaling, but in agreement given the large scatter.

arXiv comment22 pages, 16 figures, proposed for acceptance in A&A

References in corpus (112)

• Galactic Stellar and Substellar Initial Mass Function
• The Structure of Cold Dark Matter Halos
• The Global Schmidt Law in Star Forming Galaxies
• Theory of Star Formation
• E pur si muove: Galiliean-invariant cosmological hydrodynamical simulations on a moving mesh
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• Control of star formation by supersonic turbulence
• Interstellar Turbulence I: Observations and Processes
• The Neutral Atomic Phases of the ISM in the Galaxy
• A General Theory of Turbulence-Regulated Star Formation, From Spirals to ULIRGs
• Density, Velocity, and Magnetic Field Structure in Turbulent Molecular Cloud Models
• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• The Star Formation Rate of Turbulent Magnetized Clouds: Comparing Theory, Simulations, and Observations
• Re-examining Larson's Scaling Relationships in Galactic Molecular Clouds
• The Statistics of Supersonic Isothermal Turbulence
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• Structural Analysis of Molecular Clouds: Dendrograms
• Dissipation in Compressible MHD Turbulence
• The Resolved Properties of Extragalactic Giant Molecular Clouds
• The Universality of Turbulence in Galactic Molecular Clouds
• A High Order Godunov Scheme with Constrained Transport and Adaptive Mesh Refinement for Astrophysical MHD
• HOP: A New Group-Finding Algorithm for N-body Simulations
• Physical properties of molecular clouds for the entire Milky Way disk
• The SILCC (SImulating the LifeCycle of molecular Clouds) project: I. Chemical evolution of the supernova-driven ISM
• Global Hierarchical Collapse In Molecular Clouds. Towards a Comprehensive Scenario
• ATLASGAL --- properties of a complete sample of Galactic clumps
• Turbulent molecular clouds
• Physical Properties and Galactic Distribution of Molecular Clouds identified in the Galactic Ring Survey
• Thermal condensation in a turbulent atomic hydrogen flow
• RAMSES-RT: Radiation hydrodynamics in the cosmological context
• The Equilibrium State of Molecular Regions in the Outer Galaxy
• Turbulent Flow-Driven Molecular Cloud Formation: A Solution to the Post-T Tauri Problem?
• Simulating the formation of molecular clouds. I. Slow formation by gravitational collapse from static initial conditions
• Low Virial Parameters in Molecular Clouds: Implications for High Mass Star Formation and Magnetic Fields
• Turbulent Structure of a Stratified Supernova-Driven Interstellar Medium
• The Formation of Stellar Clusters: Gaussian Cloud Conditions I
• Simulating the formation of molecular clouds. II. Rapid formation from turbulent initial conditions
• Analytical star formation rate from gravoturbulent fragmentation
• The Second Survey of the Molecular Clouds in the Large Magellanic Cloud by NANTEN I: Catalog of Molecular Clouds
• The Magellanic Mopra Assessment (MAGMA). I. The Molecular Cloud Population of the Large Magellanic Cloud
• The PdBI Arcsecond Whirlpool Survey (PAWS): Environmental Dependence of Giant Molecular Cloud Properties in M51
• Gravity or Turbulence? The velocity dispersion-size relation
• Three-phase Interstellar medium in Galaxies Resolving Evolution with Star formation and Supernova feedback (TIGRESS): Algorithms, Fiducial model, and Convergence
• The SILCC (SImulating the LifeCycle of molecular Clouds) project - II. Dynamical evolution of the supernova-driven ISM and the launching of outflows
• Dispersal of molecular clouds by ionising radiation
• Molecular Cloud Formation Behind Shock Waves
• The Mass Spectra of Giant Molecular Clouds in the Local Group
• A Uniform Catalog of Molecular Clouds in the Milky Way
• Physical vs. Observational Properties of Clouds in Turbulent Molecular Cloud Models
• Disk-Halo Interaction - I. Three-Dimensional Evolution of the Galactic Disk
• Two regimes of Turbulent Fragmentation and the stellar IMF from Primordial to Present Day Star Formation
• Geometry of Star-Forming Galaxies from SDSS, 3D-HST and CANDELS
• A robust numerical scheme for highly compressible magnetohydrodynamics: Nonlinear stability, implementation and tests
• Three-dimensional interstellar dust reddening maps of the Galactic plane
• Dependence of Interstellar Turbulent Pressure on Supernova Rate
• Vertical structure of a supernova-driven turbulent magnetized ISM
• Resolving nearby dust clouds
• TreeCol: a novel approach to estimating column densities in astrophysical simulations
• Giant Molecular Cloud Catalogues for PHANGS-ALMA: Methods and Initial Results
• Molecular Gas Properties on Cloud Scales Across the Local Star-forming Galaxy Population
• Towards a more realistic sink particle algorithm for the RAMSES code
• The role of cosmic ray pressure in accelerating galactic outflows
• The link between molecular cloud structure and turbulence
• SILCC-Zoom: The dynamical and chemical evolution of molecular clouds
• Six Myths on the Virial Theorem for Interstellar Clouds
• SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium
• Giant Molecular Clouds in the Local Group Galaxy M33
• Larson's third law and the universality of molecular cloud structure
• Fractal Structure in Galactic Star Fields
• The supernova-regulated ISM. I. The multi-phase structure
• Galactic porosity and a star formation threshold for the escape of ionising radiation from galaxies
• Graph-based interpretation of the Molecular Interstellar Medium Segmentation
• Supernova feedback in a local vertically stratified medium: interstellar turbulence and galactic winds
• An Excursion-Set Model for the Structure of GMCs and the ISM
• Ion-by-ion Cooling efficiencies
• Tracing the formation of molecular clouds via [CII], [CI] and CO emission
• Resolved Giant Molecular Clouds in Nearby Spiral Galaxies: Insights from the CANON CO (1-0) Survey
• Simulations of the star-forming molecular gas in an interacting M51-like galaxy
• Feedback in Clouds II: UV Photoionisation and the first supernova in a massive cloud
• Testing Larson's relationships in massive clumps
• Tree-based solvers for adaptive mesh refinement code FLASH - I: gravity and optical depths
• Gravitational Runaway and Turbulence Driving in Star-Gas Galactic Disks
• The Effect of Projection on Derived Mass-Size and Linewidth-Size Relationships
• The integrated properties of the molecular clouds from the JCMT CO(3-2) High Resolution Survey
• Structure distribution and turbulence in self-consistently supernova-driven ISM of multiphase magnetized galactic discs
• The SILCC project - V. The impact of magnetic fields on the chemistry and the formation of molecular clouds
• A large catalogue of molecular clouds with accurate distances within 4 kpc of the Galactic disk
• The SEDIGISM survey: Molecular clouds in the inner Galaxy
• Modeling H2 formation in the turbulent ISM: Solenoidal versus compressive turbulent forcing
• On the structure of molecular clouds
• Forming early-type galaxies without AGN feedback: a combination of merger-driven outflows and inefficient star formation
• The role of galactic dynamics in shaping the physical properties of giant molecular clouds in Milky Way-like galaxies
• The Mass-Size Relation and the Constancy of GMC Surface Densities in the Milky Way
• How well does CO emission measure the H${}_2$ mass of MCs?
• Impact of galactic shear and stellar feedback on star formation
• The Forgotten Quadrant Survey. ${}^{12}$CO and ${}^{13}$CO (1-0) survey of the Galactic Plane in the range 220°$<l<$240° -2.5°$<b<$0°
• A Simple Perspective on the Mass-Area Relationship in Molecular Clouds
• Simulations of the star-forming molecular gas in an interacting M51-like galaxy: cloud population statistics
• Large-scale turbulent driving regulates star formation in high-redshift gas-rich galaxies
• Are massive dense clumps truly sub-virial? A new analysis using Gould Belt ammonia data
• A possible observational bias in the estimation of the virial parameter in virialized clumps
• What is the physics behind the Larson mass-size relation?
• Periodicity makes galactic shocks unstable - I. Linear analysis
• Alignment of the magnetic field in star forming regions and why it might be difficult to observe
• Gas Column Density Distribution of Molecular Clouds in the Third Quadrant of the Milky Way
• Molecular cloud catalogue from ${}^{13}$CO(1-0) data of the Forgotten Quadrant Survey
• The three-dimensional structure of Galactic molecular cloud complexes out to 2.5 kpc
• A Parsec-Scale Catalog of Molecular Clouds in the Solar Neighborhood Based on 3D Dust Mapping: Implications for the Mass-Size Relation
• Magnetic fields do not suppress global star formation in low metallicity dwarf galaxies
• The Role of Gravity in Producing Power-Law Mass Functions
• Large-scale turbulent driving regulates star formation in high-redshift gas-rich galaxies II: Influence of the magnetic field and the turbulent compressive fraction

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• The superclouds of the local Milky Way
• Stellar Feedback Effects on the Mass Distribution of Clouds and Cloud Complexes
• Loose threads: parsec-scale filamentation in the high Galactic latitude molecular clouds MBM 3 and MBM 16
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