A Dynamical Model for the Formation of Gas Rings and Episodic Starbursts Near Galactic Centres

Abstract

We develop a simple dynamical model for the evolution of gas in the centres of barred spiral galaxies, using the Milky Way's Central Molecular Zone (CMZ, i.e., the central few hundred pc) as a case study. We show that, in the presence of a galactic bar, gas in a disc in the central regions of a galaxy will be driven inwards by angular momentum transport induced by acoustic instabilities within the bar's inner Lindblad resonance. This transport process drives turbulence within the gas that temporarily keeps it strongly gravitationally stable and prevents the onset of rapid star formation. However, at some point the rotation curve must transition from approximately flat to approximately solid body, and the resulting reduction in shear reduces the transport rates and causes gas to build up, eventually producing a gravitationally-unstable region that is subject to rapid and violent star formation. For the observed rotation curve of the Milky Way, the accumulation happens $\sim 100$ pc from the centre of the Galaxy, in good agreement with the observed location of gas clouds and young star clusters in the CMZ. The characteristic timescale for gas accumulation and star formation is of order $10-20$ Myr. We argue that similar phenomena should be ubiquitous in other barred spiral galaxies.

19 pages, 16 figures, MNRAS in press; this version has minor revisions to the discussion and added references, no other changes

References in corpus (31)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Slow Star Formation in Dense Gas: Evidence and Implications
• The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive Forcing
• Rapid formation of exponential disks and bulges at high redshift from the dynamical evolution of clump cluster and chain galaxies
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• The impact of interactions, bars, bulges, and AGN on star formation efficiency in local massive galaxies
• The dynamical evolution of molecular clouds near the Galactic Centre - I. Orbital structure and evolutionary timeline
• Giant Magnetized Outflows from the Centre of the Milky Way
• Star Formation in the Central 400 pc of the Milky Way: Evidence for a Population of Massive YSOs
• An Ammonia Spectral Atlas of Dense Cores in Perseus
• ALMA Reveals the Molecular Medium Fueling the Nearest Nuclear Starburst
• Gas flow models in the Milky Way embedded bars
• SLUG -- Stochastically Lighting Up Galaxies. III: A Suite of Tools for Simulated Photometry, Spectroscopy, and Bayesian Inference with Stochastic Stellar Populations
• Dynamics of Dense Cores in the Perseus Molecular Cloud
• Gas flow in barred potentials
• The Bolocam Galactic Plane Survey IV: 1.1 and 0.35 mm Dust Continuum Emission in the Galactic Center Region
• A cluster in the making: ALMA reveals the initial conditions for high-mass cluster formation
• The density structure and star formation rate of non-isothermal polytropic turbulence
• Turbulence sets the initial conditions for star formation in high-pressure environments
• Early formation of massive, compact, spheroidal galaxies with classical profiles by violent disc instability or mergers
• The formation of stellar nuclear discs in bar-induced gas inflows
• G0.253+0.016: A centrally condensed, high-mass protocluster
• Galaxy Zoo: the dependence of the star formation-stellar mass relation on spiral disk morphology
• The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials
• Star formation laws and thresholds from ISM structure and turbulence
• Abundant Methanol Masers but no New Evidence for Star Formation in GCM0.253+0.016
• The Kinematics of Molecular Cloud Cores in the Presence of Driven and Decaying Turbulence: Comparisons with Observations
• Main-sequence stars masquerading as Young Stellar Objects in the central molecular zone
• Massive Star Formation in the Molecular Ring Orbiting the Black Hole at the Galactic Center
• A Test of Star Formation Laws in Disk Galaxies. II. Dependence on dynamical properties
• Absorption Filaments Towards the Massive Clump G0.253+0.016

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• A Dynamical Model for Gas Flows, Star Formation, and Nuclear Winds in Galactic Centres
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• 'The Brick' is not a brick: A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016
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• A Model for the Onset of Self-gravitation and Star Formation in Molecular Gas Governed by Galactic Forces: I. Cloud-scale Gas Motions
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• Star formation in a high-pressure environment: An SMA view of the Galactic centre dust ridge
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• A Census of Early Phase High-Mass Star Formation in the Central Molecular Zone
• The Galactic Center Molecular Cloud Survey. II. A Lack of Dense Gas & Cloud Evolution along Galactic Center Orbits
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• The EDGE-CALIFA survey: The role of spiral arms and bars in driving central molecular gas concentrations
• Detailed abundances in the Galactic center: Evidence of a metal-rich alpha-enhanced stellar population
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• H2O Southern Galactic Plane Survey (HOPS): Paper III - Properties of Dense Molecular Gas across the Inner Milky Way
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• The Atacama Cosmology Telescope: Microwave Intensity and Polarization Maps of the Galactic Center
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• The centres of M83 and the Milky Way: opposite extremes of a common star formation cycle
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• Stellar feedback in M83 as observed with MUSE -- I. Overview, an unprecedented view of the stellar and gas kinematics and evidence of outflowing gas
• Stochastic Modelling of Star Formation Histories III. Constraints from Physically-Motivated Gaussian Processes
• Spitzer Infrared Spectrograph Observations of the Galactic Center: Quantifying the Extreme Ultraviolet/so ft X-ray fluxes
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• SOFIA/HAWC+ Far-Infrared Polarimetric Large-Area CMZ Exploration (FIREPLACE) Survey III: Full Survey Data Set
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• A global view on star formation: The GLOSTAR Galactic plane survey IV. Radio continuum detections of young stellar objects in the Galactic Centre region
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• Virial Clumps in Central Molecular Zone Clouds
• Unveiling the inner morphology and gas kinematics of NGC 5135 with ALMA
• The ALMaQUEST Survey XIV: do radial molecular gas flows affect the star-forming ability of barred galaxies?
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• Investigating the link between inner gravitational potential and star-formation quenching in CALIFA galaxies
• Kinematics of Galactic Centre clouds shaped by shear-seeded solenoidal turbulence
• A mean density of $112M_{\odot }\mathrm{p}{\mathrm{c}}^{-3}$ for Central Molecular Zone clumps -- Evidences for shear-enabled pressure equilibrium in the Galactic Center
• The growth of bulges and discs in relatively HI-rich galaxies: indication from HI scaling relations
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• The life cycle of starbursting circumnuclear gas discs
• Radio continuum of galaxies with H${}_2$O megamaser disks: 33 GHz VLA data
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• The EDGE-CALIFA survey: Star formation relationships for galaxies at different stages of their evolution
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