ISM properties in hydrodynamic galaxy simulations: turbulence cascades, cloud formation, role of gravity and feedback

By Frédéric Bournaud, Bruce G. Elmegreen, Romain Teyssier, D. Block, Ivanio Puerari. 2010

188 citations recorded by the source corpus.

We study the properties of ISM substructure and turbulence in hydrodynamic (AMR) galaxy simulations with resolutions up to 0.8 pc and 5 � 10 3 M� . We analyse the power spectrum of the density distribution, and various components of the velocity field. We show that the disk thickness is about the average Jeans scale length, and is mainly regulated by gravitational instabilities. From this scale of energy injection, a turbulence cascade towards small-scale is observed, with almost isotropic small-scale motions. On scales larger than the disk thickness, density waves are observed, but there is also a full range of substructures with chaotic and strongly non-isotropic gas velocity dispersions. The power spectrum of vorticity in an LMC-sized model suggests that an inverse cascade of turbulence might be present, although energy input over a wide range of scales in the coupled gaseous+stellar fluid could also explain this quasi-2D regime on scales larger than the disk scale height. Similar regimes of gas turbulence are also found in massive high-redshift disks with high gas fractions. Disk properties and ISM turbulence appear to be mainly regulated by gravitational processes, both on large scales and inside dense clouds. Star formation feedback is however essential to maintain the ISM in a steady state by balancing a systematic gas dissipation into dense and small clumps. Our galaxy simulations employ a thermal model based on a barotropic Equation of State (EoS) aimed at modelling the equilibrium of gas between various heating and cooling processes. Denser gas is typically colder in this approach, which is shown to correctly reproduce the density structures of a star-forming, turbulent, unstable and cloudy ISM down to scales of a few parsecs.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/b896f9179c49d51e2e1203b84cd7e4163534945d

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Citations in the corpus

Turbulent molecular clouds (2012, background): “…approach treats a whole galactic disk in- cluding the gravity of stars either in a fixed asymmetric potential (e.g. Tasker & Tan 2009), or in a prescribed spiral arm potential (e.g. Dobbs & Bonnell 2007) or with self–consistent dynamics of stars (e.g. Bournaud et al. 2010, Hopkins et al. 2011).”
The ATLAS3D project – I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria (2010, methodology): “Following the technique developed in Bournaud et al. (2010), we model the dynamics of atomic and molecular gas disks in early-type galaxies with parsec-scale resolution, based on accurate mass models extracted from the ATLAS3D data.”
Wet Disc Contraction to Galactic Blue Nuggets and Quenching to Red Nuggets (2013, background): “Stellar feedback, by supernovae and radiation pressure, may or may not be a major direct driver of the turbulence (Dekel, Sari & Ceverino 2009; Bournaud et al. 2010; Krumholz & Thompson 2013).”
Toy models for galaxy formation versus simulations (2013, background): “There is potentially enough energy and momentum in supernovae, radiative feedback and winds (Dekel, Sari & Ceverino 2009; Bournaud et al. 2010; Krumholz & Thompson 2012, 2013; Dekel & Krumholz 2013), but it is not clear whether they are properly deposited within the disc.”
A general model for the CO–H2 conversion factor in galaxies with applications to the star formation law (2011, background): “With high SFRs come hotter dust temperatures as the UV radiation heats the nearby dust grains.”
Physical Models of Galaxy Formation in a Cosmological Framework (2014, methodology): “RAMSES: A new N-body and hydrodynamical code.”
The structure of the interstellar medium of star‐forming galaxies (2011, background): “Bournaud et al. (2010) also explicitly showed that 12 This collapse might be very different in the presence of magnetic fields which can torque the GMCs and remove this angular momentum.”
Rotational support of giant clumps in high-z disc galaxies (2011, methodology): “The technique relies on a quasi-Lagrangian refinement of the AMR grid and a barotropic equation of state for the heterogeneous ISM (Teyssier et al. 2010; Bournaud et al. 2010).”
THE KMOS3D SURVEY: DESIGN, FIRST RESULTS, AND THE EVOLUTION OF GALAXY KINEMATICS FROM 0.7 ⩽ z ⩽ 2.7 (2014, background): “…2010), conversion of gravitational potential energy into random motions either at the outer disk/cosmic web boundary (Förster Schreiber et al. 2006; Genzel et al. 2006, 2008), or in the inner disk by torques in clump-clump interactions (Immeli et al. 2004; Bournaud et al. 2010; Aumer et al. 2010).”
THE LONG LIVES OF GIANT CLUMPS AND THE BIRTH OF OUTFLOWS IN GAS-RICH GALAXIES AT HIGH REDSHIFT (2013, methodology): “Note that simulated molecular clouds in lowredshift galaxies were found to be short-lived and unvirialized even when only some of the feedback modes are included (e.g., Tasker 2011; Bournaud et al. 2010; Ceverino et al. 2012).”
A sub-parsec resolution simulation of the Milky Way: global structure of the interstellar medium and properties of molecular clouds (2013, methodology): “In the Milky Way, the contrast between spirals and interarms is much stronger than in the LMC, mostly because of a higher rotation velocity and thus stronger spiral shocks.”
FIRE-2 simulations: physics versus numerics in galaxy formation (2017, background): “…of stellar feedback, most gas accreted into galaxies should cool rapidly on a timescale much shorter than the dynamical time, collapse, fragment, and turn into stars (Bournaud et al. 2010; Tasker 2011; Hopkins et al. 2011; Dobbs et al. 2011; Krumholz et al. 2011; Harper-Clark & Murray 2011).”
How Stellar Feedback Simultaneously Regulates Star Formation and Drives Outflows (2015, methodology): “The other commonly used technique is the ‘blastwave’ model, in which thermal energy is injected into the ISM surrounding supernova particles (e.g.Katz et al. 1996; Thacker & Couchman 2000; Stinson et al. 2006, 2013; Governato et al. 2007, 2010, 2012; Dubois & Teyssier 2008; Bournaud et al. 2010).”
Self-regulated star formation in galaxies via momentum input from massive stars (2011, methodology): “…user on 21 M ay 2020 can now reach the resolution required to resolve the formation of GMCs, ∼1–100 pc (see e.g. Saitoh et al. 2008; Tasker & Tan 2009; Bournaud et al. 2010; Dobbs, Burkert & Pringle 2011) (note that GMCs in massive gas-rich galaxies are ∼ kpc in size, significantly larger than…”
A UNIVERSAL, LOCAL STAR FORMATION LAW IN GALACTIC CLOUDS, NEARBY GALAXIES, HIGH-REDSHIFT DISKS, AND STARBURSTS (2011, unknown): “For Bournaud et al. (2010), ∆x = 0.8 pc, so artificial pressure dominates at densities above 3800 H cm−3.”
Ionized gas outflows and global kinematics of low-z luminous star-forming galaxies (2014, background): “It has been proposed that this extranuclear star formation is triggered by an increase of the ISM turbulence as a consequence of the tidal interaction (Elmegreen et al. 2000; Struck et al. 2005; Bournaud et al. 2010).”
Star formation in galaxy mergers with realistic models of stellar feedback and the interstellar medium (2012, background): “Numerical simulations of isolated galaxies and galaxy mergers can now achieve the dynamic range required to resolve the formation of GMC and ISM structure, ∼1–10 pc (see e.g. Saitoh et al. 2008; Tasker & Tan 2009; Bournaud et al. 2010; Dobbs, Burkert & Pringle 2011).”
THREE-DIMENSIONAL HYDRODYNAMIC SIMULATIONS OF MULTIPHASE GALACTIC DISKS WITH STAR FORMATION FEEDBACK. I. REGULATION OF STAR FORMATION RATES (2013, background): “…Kim et al. 2006, 2010; Dobbs & Bonnell 2006), magnetorotational instability (Kim et al. 2003; Piontek & Ostriker 2005, 2007), large-scale gravitational instabilities (Wada & Norman 2002; Kim & Ostriker 2007; Agertz et al. 2009; Bournaud et al. 2010), and cosmic inflow (Klessen & Hennebelle 2010).”
BLACK HOLE GROWTH AND ACTIVE GALACTIC NUCLEI OBSCURATION BY INSTABILITY-DRIVEN INFLOWS IN HIGH-REDSHIFT DISK GALAXIES FED BY COLD STREAMS (2011, methodology): “Figure 1 shows two snapshots of run HR1.”