The James Clerk Maxwell Telescope Nearby Galaxies Legacy Survey IX: ${}^{12}$CO $J=3\to 2$ Observations of NGC 2976 and NGC 3351

Abstract

We present ${}^{12}$CO \textit{J=3$\to$2} maps of NGC 2976 and NGC 3351 obtained with the James Clerk Maxwell Telescope (JCMT), both early targets of the JCMT Nearby Galaxy Legacy Survey (NGLS). We combine the present observations with ${}^{12}$CO \textit{J=1$\to$0} data and find that the computed ${}^{12}$CO \textit{J=3$\to$2} to ${}^{12}$CO \textit{J=1$\to$0} line ratio ($R_{31}$) agrees with values measured in other NGLS field galaxies. We compute the M${}_{{\mathrm{H}}_2}$ value and find that it is robust against the value of $R_{31}$ used. Using \textsc{Hi} data from the The \textsc{Hi} Nearby Galaxy Survey (THINGS) survey, we find a tight correlation between surface density of H${}_2$ and star formation rate density for NGC 3351 when ${}^{12}$CO \textit{J=3$\to$2} data are used. Finally, we compare the ${}^{12}$CO \textit{J=3$\to$2} intensity with the PAH 8 $\mu$m surface brightness and find a good correlation in the high surface brightness regions. We extend this study to include all 25 \textit{Spitzer} Infrared Nearby Galaxies Survey (SINGS) galaxies within the NGLS sample and find a tight correlation at large spatial scales. We suggest that both PAH 8 $\mu$m and ${}^{12}$CO \textit{J=3$\to$2} are likely to originate in regions of active star formation.

15 pages, 10 figures Monthly Notices of Royal Astronomical Society 2013

References in corpus (8)

• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• A Molecular Star Formation Law in the Atomic Gas Dominated Regime in Nearby Galaxies
• The Behavior of the Aromatic Features in M101 HII Regions: Evidence for Dust Processing
• The JCMT Nearby Galaxies Legacy Survey I. Star Forming Molecular Gas in Virgo Cluster Spiral Galaxies
• The Incidence of Highly-Obscured Star-Forming Regions in SINGS Galaxies
• The JCMT Nearby Galaxies Legacy Survey VIII. CO data and the L(CO3-2)-L(FIR) correlation in the SINGS sample
• The relationship between gas content and star formation rate in spiral galaxies. Comparing the local field with the Virgo cluster
• Kinematics of gas and stars in the circumnuclear starforming ring of NGC 3351

Cited by in corpus (6)

• GMCs scaling relations: role of the cloud definition
• Molecular transitions as probes of the physical conditions of extragalactic environments
• The relationship between polycyclic aromatic hydrocarbon emission and far-infrared dust emission from NGC 2403 and M83
• Relation between parameters of dust and parameters of molecular and atomic gas in extragalactic star-forming regions
• Studies of the distinct regions due to CO selective dissociation in the Aquila molecular cloud
• The JCMT Nearby Galaxies Legacy Survey: SCUBA-2 observations of nearby galaxies