Molecular clouds as hubs in spiral galaxies: gas inflow and evolutionary sequence

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A90106%2F24%3A00617608" target="_blank" >RIV/67985815:90106/24:00617608 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1093/mnras/stae2101" target="_blank" >https://doi.org/10.1093/mnras/stae2101</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stae2101" target="_blank" >10.1093/mnras/stae2101</a>

Result language

angličtina

Original language name

Molecular clouds as hubs in spiral galaxies: gas inflow and evolutionary sequence

Original language description

We decomposed the molecular gas in the spiral galaxy NGC 628 (M74) into multiscale hub-filament structures using the CO (2$-$1) line by the dendrogram algorithm. All leaf structures as potential hubs were classified into three categories, i.e. leaf-HFs-A, leaf-HFs-B and leaf-HFs-C. Leaf-HFs-A exhibit the best hub-filament morphology, which also have the highest density contrast, the largest mass and the lowest virial ratio. We employed the filfinder algorithm to identify and characterize filaments within 185 leaf-HFs-A structures, and fitted the velocity gradients around the intensity peaks. Measurements of velocity gradients provide evidence for gas inflow within these structures, which can serve as a kinematic evidence that these structures are hub-filament structures. The numbers of the associated 21 mu m and H alpha structures and the peak intensities of 7.7 mu m, 21 mu m, and H alpha emissions decrease from leaf-HFs-A to leaf-HFs-C. The spatial separations between the intensity peaks of CO and 21 mu m structures of leaf-HFs-A are larger than those of leaf-HFs-C. These evidence indicate that leaf-HFs-A are more evolved than leaf-HFs-C. There may be an evolutionary sequence from leaf-HFs-C to leaf-HFs-A. Currently, leaf-HFs-C lack a distinct gravitational collapse process that would result in a significant density contrast. The density contrast can effectively measure the extent of the gravitational collapse and the depth of the gravitational potential of the structure which, in turn, shapes the hub-filament morphology. Combined with the kinematic analysis presented in previous studies, a picture emerges that molecular gas in spiral galaxies is organized into network structures through the gravitational coupling of multiscale hub-filament structures. Molecular clouds, acting as knots within these networks, serve as hubs, which are local gravitational centres and the main sites of star formation.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

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Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

1365-2966

Volume of the periodical

534

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

12

Pages from-to

683-694

UT code for WoS article

001318794500004

EID of the result in the Scopus database

2-s2.0-85204955269