ALMA FACTS. II. Large Scale Variations in the 12CO(J=2-1) to 12CO(J=1-0) Line Ratio in Nearby Galaxies

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A90106%2F25%3A00646431" target="_blank" >RIV/67985815:90106/25:00646431 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3847/1538-4357/ada6b5" target="_blank" >https://doi.org/10.3847/1538-4357/ada6b5</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ada6b5" target="_blank" >10.3847/1538-4357/ada6b5</a>

Result language

angličtina

Original language name

ALMA FACTS. II. Large Scale Variations in the 12CO(J=2-1) to 12CO(J=1-0) Line Ratio in Nearby Galaxies

Original language description

We present 12CO(J = 1 0) mapping observations over similar to 1/2 of the optical disk of 12 nearby galaxies from the Fundamental CO 1-0 Transition Survey of nearby galaxies (FACTS), using the ALMA Total Power array. Variations in the 12CO(J = 2 1)/12CO(J = 1 0) line ratio r21 are investigated. The luminosity-weighted r21 of the 11 sample galaxies ranges from 0.52 to 0.69 with an average of 0.61. We use position-velocity diagrams along the major axis and tilted ring models to separate the normal rotating galactic disk from kinematic outliers that deviate from pure circular rotation. We find that r21 is systematically higher in outliers compared to the disk. We compare r21 between SA, SAB, and SB galaxies, and find no significant difference in the average r21 depending on the presence of galactic bars. We find, however, that the radial gradient in r21 is bimodal, where a group containing all SA galaxies prefer constant or very shallow r21 gradients out to 40% of the optical radius, while another group containing all SB galaxies have a steep r21 gradient, decreasing by similar to 20% before 40% of the optical radius, which also corresponds to the radius of the stellar bar. After this radius, these galaxies become consistent with a constant or shallow trend in r21. The large scale trend in r21 can have implications for how we interpret observations made solely in the 12CO(J = 2 1) line.

Czech name

—

Czech description

—

Type

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

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

—

Publication year

2025

Confidentiality

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

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

980

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

15

Pages from-to

126

UT code for WoS article

001415708300001

EID of the result in the Scopus database

2-s2.0-85217260130