Quantitative analysis of the molecular gas morphology in nearby disk galaxies

Abstract

We present a quantitative and statistical analysis of the molecular gas morphology in 73 nearby galaxies using high spatial resolution CO ($J$ = 2-1) data obtained from the Atacama Large Millimeter/submillimeter Array (ALMA) by the PHANGS large program. We applied three model-independent parameters: Concentration ($C$), Asymmetry ($A$), and Clumpiness ($S$) which are commonly used to parameterize the optical and infrared morphology of galaxies. We find a clear apparent correlation between $A$ and $S$, with a Spearman's rank correlation coefficient of $0.52$ with a $p$-value of $2\times 10^{-6}$. This suggests a higher abundance of molecular clumps (i.e. giant molecular cloud associations) in galaxies that display stronger distortion or biased large-scale molecular gas distribution. In addition, the analysis of the $C$ parameter suggests high central molecular concentration in most barred spiral galaxies investigated in this study. Furthermore, we found a positive correlation between the length of the bar structure ($R_{\mathrm{bar}}/R_{25}$) and the $C$ parameter, with a Spearman's rank correlation coefficient of $0.63$ with a $p$-value of $3.8\times 10^{-5}$, suggesting that larger bar structure can facilitate overall molecular gas transport and yield higher central concentration than galaxies with shorter bars. Finally, we offer a possible classification scheme of nearby disk galaxies which is based on the CAS parameters of molecular gas.

20 pages, 24 figures, 4 Tables

References in corpus (24)

• Array Programming with NumPy
• The Evolution of Galaxy Structure over Cosmic Time
• A Classical Morphological Analysis of Galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G)
• The Dawes Review 9: The role of cold gas stripping on the star formation quenching of satellite galaxies
• PHANGS-ALMA Data Processing and Pipeline
• PHANGS CO kinematics: disk orientations and rotation curves at 150 pc resolution
• Giant Molecular Cloud Catalogues for PHANGS-ALMA: Methods and Initial Results
• Stellar structures, molecular gas, and star formation across the PHANGS sample of nearby galaxies
• Panic! At the Disks: First Rest-frame Optical Observations of Galaxy Structure at $z>3$ with JWST in the SMACS 0723 Field
• New Constraints on the ${}^{12}$CO(2-1)/(1-0) Line Ratio Across Nearby Disc Galaxies
• The Properties and Evolution of a K-band Selected Sample of Massive Galaxies at z~0.4 - 2 in the Palomar/DEEP2 Survey
• CI and CO in nearby galaxy centers: the bright galaxies NGC1068 (M77), NGC2146, NGC3079, NGC4826 (M64), and NGC7469
• CO Multi-line Imaging of Nearby Galaxies (COMING). IX. ${}^{12}$CO($J$=2-1)/${}^{12}$CO($J$=1-0) line ratio on kiloparsec scales
• WISDOM Project -- X. The morphology of the molecular ISM in galaxy centres and its dependence on galaxy structure
• The two formation pathways of S0 galaxies
• The SAMI Galaxy Survey: A Range in S0 Properties Indicating Multiple Formation Pathways
• The Gas Morphology of Nearby Star-Forming Galaxies
• Formation of S0s in extreme environments I: clues from kinematics and stellar populations
• CO($J$=1-0) mapping survey of 64 galaxies in the Fornax cluster with the ALMA Morita array
• Embedded Young Massive Star Clusters in the Antennae Merger
• Two physical regimes for the Giant HII Regions and Giant Molecular Clouds in the Antennae Galaxies
• ALMA/ACA CO Survey of the IC 1459 and NGC 4636 Groups: Environmental Effects on the Molecular Gas of Group Galaxies
• CO Excitation and its Connection to Star Formation at 200 pc in NGC 1365
• VERTICO VI: Cold-gas asymmetries in Virgo cluster galaxies

Cited by in corpus (1)

• Galaxy Activity, Torus and Outflow Survey (GATOS) X: Molecular gas clumpiness under the influence of AGN