PHANGS-MeerKAT and MHONGOOSE HI observations of nearby spiral galaxies: Physical drivers of the molecular gas fraction, Rmol

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A90106%2F24%3A00617499" target="_blank" >RIV/67985815:90106/24:00617499 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1051/0004-6361/202449944" target="_blank" >https://doi.org/10.1051/0004-6361/202449944</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202449944" target="_blank" >10.1051/0004-6361/202449944</a>

Result language

angličtina

Original language name

PHANGS-MeerKAT and MHONGOOSE HI observations of nearby spiral galaxies: Physical drivers of the molecular gas fraction, Rmol

Original language description

The molecular-to-atomic gas ratio is crucial to our understanding of the evolution of the interstellar medium (ISM) in galaxies. We investigated the balance between the atomic (Sigma(HI)) and molecular gas (Sigma(H2)) surface densities in eight nearby star-forming galaxies using new high-quality observations from MeerKAT and ALMA (for H I and CO, respectively). We defined the molecular gas ratio as R-mol = Sigma(H2)/Sigma(HI) and measured how R-mol depends on local conditions in the galaxy disks using multiwavelength observations. We find that, depending on the galaxy, H I is detected at > 3 sigma out to 20 120 kpc in galactocentric radius (r(gal)). The typical radius at which Sigma(HI) reaches 1 M-circle dot pc(-2) is r(H I) approximate to 22 kpc, which corresponds to 1 3 times the optical radius (r(25)). We note that, R-mol correlates best with the dynamical equilibrium pressure, P-DE, among potential drivers studied, with a median correlation coefficient of <rho > = 0.89. Correlations between R-mol and the star formation rate surface density, total gas surface density, stellar surface density, metallicity, and Sigma(SFR)/P-DE (a proxy for the combined effect of the UV radiation field and number density) are present but somewhat weaker. Our results also show a direct correlation between P-DE and Sigma(SFR), supporting self-regulation models. Quantitatively, we measured similar scalings as previous works, and attribute the modest differences that we do find to the effect of varying resolution and sensitivity. At r(gal) greater than or similar to 0.4r(25), atomic gas dominates over molecular gas among our studied galaxies, and at the balance of these two gas phases (R-mol = 1), we find that the baryon mass is dominated by stars, with Sigma(*) > 5 Sigma(gas). Our study constitutes an important step in the statistical investigation of how local galaxy properties (stellar mass, star formation rate, or morphology) impact the conversion from atomic to molecular gas in nearby galaxies.

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

—

Continuities

—

Publication year

2024

Confidentiality

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

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

691

Issue of the periodical within the volume

Nov.

Country of publishing house

FR - FRANCE

Number of pages

24

Pages from-to

A163

UT code for WoS article

001353369000006

EID of the result in the Scopus database

2-s2.0-85209678609