Molecular gas in M83 consists of two log-normal density components, with the high-density component enhanced along spiral arms and more tightly linked to star formation than the low-density component.
The Exciting Lives of Giant Molecular Clouds
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
We present a detailed study of the evolution of GMCs in a galactic disc simulation. We follow individual GMCs (defined in our simulations by a total column density criterion), including their level of star formation, from their formation to dispersal. We find the evolution of GMCs is highly complex. GMCs often form from a combination of smaller clouds and ambient ISM, and similarly disperse by splitting into a number of smaller clouds and ambient ISM. However some clouds emerge as the result of the disruption of a more massive GMC, rather than from the assembly of smaller clouds. Likewise in some cases, clouds accrete onto more massive clouds rather than disperse. Because of the difficulty of determining a precursor or successor of a given GMC, determining GMC histories and lifetimes is highly non-trivial. Using a definition relating to the continuous evolution of a cloud, we obtain lifetimes typically of 4-25 Myr for >10^5 M$_{\odot}$ GMCs, over which time the star formation efficiency is about 1 %. We also relate the lifetime of GMCs to their crossing time. We find that the crossing time is a reasonable measure of the actual lifetime of the cloud, although there is considerable scatter. The scatter is found to be unavoidable because of the complex and varied shapes and dynamics of the clouds. We study cloud dispersal in detail and find both stellar feedback and shear contribute to cloud disruption. We also demonstrate that GMCs do not behave as ridge clouds, rather massive spiral arm GMCs evolve into smaller clouds in inter-arm spurs.
years
2026 2verdicts
UNVERDICTED 2representative citing papers
Simulations of collapsing cores find that ε_ff varies with core definition via density threshold, open vs closed boundaries, and initial density, with higher values in low-mass cores due to lower infall rates.
citing papers explorer
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Sub-kpc scale gas density histograms of the nearby barred spiral galaxy M83: Multi-component molecular gas structure reflecting the galactic environment
Molecular gas in M83 consists of two log-normal density components, with the high-density component enhanced along spiral arms and more tightly linked to star formation than the low-density component.
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The efficiency per free-fall time as a ratio of the Star Formation Rate to the gas-infall rate in collapsing cores: dependence on the core definition, accretion, and radial structure
Simulations of collapsing cores find that ε_ff varies with core definition via density threshold, open vs closed boundaries, and initial density, with higher values in low-mass cores due to lower infall rates.