The life cycle of giant molecular clouds in simulated Milky Way-mass galaxies
arXiv:2502.12256 · doi:10.1051/0004-6361/202554126
Abstract
In this work, we trace the complete life cycle of individual GMCs in high-resolution Milky Way-mass galaxy simulations to determine how different stellar feedback mechanisms and galactic-scale processes govern cloud lifetimes, mass evolution, and local star formation efficiency (SFE). We identify GMCs in simulated galaxies and track their evolution using cloud evolution trees. Via cloud evolution trees, we quantify the lifetimes and SFE of GMCs. We further apply our diagnostics on a suite of simulations with varying star formation and stellar feedback subgrid models and explore their impact together with galactic environments to the GMC life cycles. Our analysis reveals that GMCs undergo dynamic evolution, characterized by continuous gas accretion, gravitational collapse, and star formation, followed by disruption due to stellar feedback. The accretion process sustains the gas content throughout most of the GMC life cycles, resulting in a positive correlation between GMC lifetimes and their maximum masses. The GMC lifetimes range from a few to several tens of Myr, with two distinct dynamical modes: (1) GMCs near the galactic center experience strong tidal disturbances, prolonging their lifetimes when they remain marginally unbound; (2) those in the outer regions are less affected by tides, remain gravitationally bound, and evolve more rapidly. In all model variations, we observe that GMC-scale SFE correlates with the baryonic surface density of GMCs, consistent with previous studies of isolated GMCs. Additionally, we emphasize the critical role of galactic shear in regulating GMC-scale star formation and refine the correlation between local SFE and surface density by including its effects. These findings demonstrate how stellar feedback and galactic-scale dynamics jointly shape GMC-scale star formation in realistic galactic environments.
12 pages, 9 figures; A&A in press; abstract slightly abridged; comments welcome
References in corpus (32)
- Star Formation and Feedback in Smoothed Particle Hydrodynamic Simulations--I. Isolated Galaxies
- Physical properties of molecular clouds for the entire Milky Way disk
- The lifecycle of molecular clouds in nearby star-forming disc galaxies
- Star Formation in Disk Galaxies. I. Formation and Evolution of Giant Molecular Clouds via Gravitational Instability and Cloud Collisions
- Fast and inefficient star formation due to short-lived molecular clouds and rapid feedback
- Introducing the NewHorizon simulation: Galaxy properties with resolved internal dynamics across cosmic time
- Observational Evidence of Dynamic Star Formation Rate in Milky Way Giant Molecular Clouds
- Star cluster formation in cosmological simulations. I. Properties of young clusters
- FIRE-3: Updated Stellar Evolution Models, Yields, & Microphysics and Fitting Functions for Applications in Galaxy Simulations
- The frequency and nature of `cloud-cloud collisions' in galaxies
- Molecular Cloud Populations in the Context of Their Host Galaxy Environments: A Multiwavelength Perspective
- The GRIFFIN project -- Formation of star clusters with individual massive stars in a simulated dwarf galaxy starburst
- Heart of Darkness: the influence of galactic dynamics on quenching star formation in galaxy spheroids
- Star Formation Relations in the Milky Way
- Star Formation Laws and Efficiencies across 80 Nearby Galaxies
- Disruption of giant molecular clouds and formation of bound star clusters under the influence of momentum stellar feedback
- A model for the formation of stellar associations and clusters from giant molecular clouds
- Modeling UV Radiation Feedback from Massive Stars: I. Implementation of Adaptive Ray Tracing Method and Tests
- Introducing EMP-Pathfinder: modelling the simultaneous formation and evolution of stellar clusters in their host galaxies
- Formation and evolution of young massive clusters in galaxy mergers: the SMUGGLE view
- The Single-Cloud Star Formation Relation
- Evolution of giant molecular clouds across cosmic time
- On the Observed Diversity of Star Formation Efficiencies in Giant Molecular Clouds
- RIGEL: Simulating dwarf galaxies at solar mass resolution with radiative transfer and feedback from individual massive stars
- The global structure of magnetic fields and gas in simulated Milky Way-analogue galaxies
- A scaling relation for the molecular cloud lifetime in Milky Way-like galaxies
- Cosmological simulations of the same spiral galaxy: the impact of baryonic physics
- Calibration of a star formation and feedback model for cosmological simulations with Enzo
- Towards a multi-tracer timeline of star formation in the LMC -- II. The formation and destruction of molecular clouds
- Impact of H-driven star formation and stellar feedback from low-enrichment environments on the formation of spiral galaxies
- Playing with FIRE: A Galactic Feedback-Halting Experiment Challenges Star Formation Rate Theories
- Intertwined Formation of , Dust, and Stars in Cosmological Simulations