Effects of Varying Mass Inflows on Star Formation in Nuclear Rings of Barred Galaxies

Abstract

Observations indicate that the star formation rate (SFR) of nuclear rings varies considerably with time and is sometimes asymmetric rather than being uniform across a ring. To understand what controls temporal and spatial distributions of ring star formation, we run semi-global, hydrodynamic simulations of nuclear rings subject to time-varying and/or asymmetric mass inflow rates. These controlled variations in the inflow lead to variations in the star formation, while the ring orbital period ($18\mathrm{Myr}$) and radius ($600\mathrm{pc}$) remain approximately constant. We find that both the mass inflow rate and supernova feedback affect the ring SFR. An oscillating inflow rate with period $\Delta {\tau }_{\text{in}}$ and amplitude 20 causes large-amplitude (a factor of $\gtrsim 5$), quasi-periodic variations of the SFR, when $\Delta {\tau }_{\text{in}}\gtrsim 50\mathrm{Myr}$. We find that the time-varying ISM weight and midplane pressure track each other closely, establishing an instantaneous vertical equilibrium. The measured time-varying depletion time is consistent with the prediction from self-regulation theory provided the time delay between star formation and supernova feedback is taken into account. The supernova feedback is responsible only for small-amplitude (a factor of $\sim 2$) fluctuations of the SFR with a timescale $\lesssim 40\mathrm{Myr}$. Asymmetry in the inflow rate does not necessarily lead to asymmetric star formation in nuclear rings. Only when the inflow rate from one dust lane is suddenly increased by a large factor, the rings undergo a transient period of lopsided star formation.

15 pages, 6 figures, accepted for publication in ApJ. Replaced with minor text corrections

References in corpus (23)

• Athena: A New Code for Astrophysical MHD
• Momentum Injection by Supernovae in the Interstellar Medium
• The dynamical evolution of molecular clouds near the Galactic Centre - I. Orbital structure and evolutionary timeline
• Superbubbles in the Multiphase ISM and the Loading of Galactic Winds
• 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
• Star Formation Efficiency and Dispersal of Giant Molecular Clouds with UV Radiation Feedback: Dependence on Gravitational Boundedness and Magnetic Fields
• Simulations of the Milky Way's central molecular zone -- I. Gas dynamics
• A Connection between Star Formation in Nuclear Rings and their Host Galaxies
• Simulations of the Milky Way's central molecular zone -- II. Star formation
• Mass inflow rate into the Central Molecular Zone: observational determination and evidence of episodic accretion
• The Star Formation History and Evolution of the Circumnuclear Region of M100
• Effects of Gas on Formation and Evolution of Stellar Bars and Nuclear Rings in Disk Galaxies
• Star formation and stellar populations across nuclear rings in galaxies
• A Measurement of the Black-Hole Mass in NGC 1097 using ALMA
• Star Formation Rates of Massive Molecular Clouds in the Central Molecular Zone
• Dynamically Driven Inflow onto the Galactic Center and its Effect upon Molecular Clouds
• The dynamical evolution of molecular clouds near the Galactic Centre -- III. Tidally--induced star formation in protocluster clouds
• From kpcs to the central parsec of NGC 1097: feeding star formation and a black hole at the same time
• CMZoom II: Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone
• Star Formation in Nuclear Rings with the TIGRESS Framework
• The centres of M83 and the Milky Way: opposite extremes of a common star formation cycle
• Effects of Spiral Arms on Star Formation in Nuclear Rings of Barred-spiral Galaxies

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• Pressure-Regulated, Feedback-Modulated Star Formation In Disk Galaxies
• Introducing TIGRESS-NCR: I. Co-Regulation of the Multiphase Interstellar Medium and Star Formation Rates
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• The ALMOND Survey: Molecular cloud properties and gas density tracers across 25 nearby spiral galaxies with ALMA
• Fuelling the nuclear ring of NGC 1097
• Effects of Magnetic Fields on Gas Dynamics and Star Formation in Nuclear Rings
• Unraveling Joint Evolution of Bars, Star Formation, and Active Galactic Nuclei of Disk Galaxies
• Impact of star formation models on the growth of simulated galaxies at high redshifts
• Seeking Self-Regulating Simulations of Idealized Milky Way-Like Galaxies
• Self-consistent modelling of the Milky Way's Nuclear Stellar Disc