open access

https://hdl.handle.net/2115/79836

CO Multi-line Imaging of Nearby Galaxies (COMING). IV. Overview of the project

英語

surveys

2019-12

Oxford University Press

Publications of the astronomical society of Japan

71

S14

Observations of the molecular gas in galaxies are vital to understand the evolution and star-forming histories of galaxies. However, galaxies with molecular gas maps of their whole discs at sufficient resolution to distinguish galactic structures are severely lacking. Millimeter-wavelength studies at a high angular resolution across multiple lines and transitions are particularly needed, severely limiting our ability to infer the universal properties of molecular gas in galaxies. Hence, we conducted a legacy project with the 45 m telescope of the Nobeyama Radio Observatory, called the CO Multi-line Imaging of Nearby Galaxies (COMING), which simultaneously observed 147 galaxies with high far-infrared (FIR) flux in (CO)-C-12, (CO)-C-13, and (CO)-O-18 J = 1-0 lines. The total molecular gas mass was derived using the standard CO-to-H-2 conversion factor and found to be positively correlated with the total stellar mass derived from the WISE 3.4 mu m band data. The fraction of the total molecular gas mass to the total stellar mass in galaxies does not depend on their Hubble types nor the existence of a galactic bar, although when galaxies in individual morphological types are investigated separately, the fraction seems to decrease with the total stellar mass in early-type galaxies and vice versa in late-type galaxies. No differences in the distribution of the total molecular gas mass, stellar mass, or the total molecular gas to stellar mass ratio was observed between barred and non-barred galaxies, which is likely the result of our sample selection criteria, in that we prioritized observing FIR bright (and thus molecular gas-rich) galaxies.

学術雑誌論文

Accepted Manuscript

This is a pre-copyedited, author-produced version of an article accepted for publication in Publications of the Astronomical Society of Japan following peer review. The version of record CO Multi-line Imaging of Nearby Galaxies (COMING). IV. Overview of the project is available online at: https://academic.oup.com/pasj/article/71/Supplement_1/S14/5629162 and https://doi.org/10.1093/pasj/psz115.

0004-6264