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Table · dataset · 2025

WISDOM Proj XII ALMA CO(2-1) of clumps and clouds

Listed in IVOA Registry (Virtual Observatory)

We present a study of molecular structures (clumps and clouds) in the dwarf galaxy NGC 404 using high-resolution (~0.86

Description

  • 0.51 pc^2^) Atacama Large Millimeter/sub-millimeter Array ^12^CO(2-1) observations. We find two distinct regions in NGC 404: a gravitationally stable central region (Toomre parameter Q = 3-30) and a gravitationally unstable molecular ring (Q <~ 1). The molecular structures in the central region have a steeper size-linewidth relation and larger virial parameters than those in the molecular ring, suggesting gas is more turbulent in the former. In the molecular ring, clumps exhibit a shallower mass-size relation and larger virial parameters than clouds, implying density structures and dynamics are regulated by different physical mechanisms at different spatial scales. We construct an analytical model of clump-clump collisions to explain the results in the molecular ring. We propose that clump-clump collisions are driven by gravitational instabilities coupled with galactic shear, which lead to a population of clumps whose accumulation lengths (i.e. average separations) are approximately equal to their tidal radii. Our model-predicted clump masses and sizes (and mass-size relation) and turbulence energy injection rates (and size-linewidth relation) match the observations in the molecular ring very well, suggesting clump-clump collisions are the main mechanism regulating clump properties and gas turbulence in that region. As expected, our collision model does not apply to the central region, where turbulence is likely driven by clump migration.

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Catalogue records · 2

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Stated by source
Millimeter · Radio
Provenance · 1 source records, 9 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/mnras/517/63213 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[field].local:field:astronomymapping · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:millimetersource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:radiosource · IVOA Registryconnector:ivoa_registry@1.0.0
descriptionsource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_description
license_textsource · IVOA Registryconnector:ivoa_registry@1.0.0
publication_datesource · IVOA Registryconnector:ivoa_registry@1.0.0
titlesource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_title
updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0