Three isotopologues CO survey of Molecular Clouds in the CMa OB1 complex

Abstract

Using the Purple Mountain Observatory 13.7-m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of ${}^{12}$CO, ${}^{13}$CO, and \xxco ($J$ = 1--0) toward the CMa OB1 complex with a sky coverage of 16.5 deg${}^2$ ($221^{\circ }.5\le l\le 227^{\circ }$, $-2^{\circ }.5\le b\le 0^{\circ }.5$). Emission from the CMa OB1 complex is found in the range 7 km s${}^{-1}\le$ V${}_{\mathrm{LSR}}\le$ 25 km s${}^{-1}$. The large-scale structure, physical properties and chemical abundances of the molecular clouds are presented. A total of 83 C${}^{18}$O molecular clumps are identified with GaussClumps algorithm within the mapped region. We find that 94% of these C${}^{18}$O molecular clumps are gravitationally bound. The relationship between their size and mass indicates that none of the C${}^{18}$O clump has the potential to form high-mass stars. Using semi-automatic IDL algorithm, we newly discover 85 CO outflow candidates in the mapped area, including 23 bipolar outflows candidates. Additionally, a comparative study reveals evidence for significant variety of physical properties, evolutionary stages, and levels of star formation activity in different sub-regions of the CMa OB1 complex.

31 pages, 20 figures, 10 tables, accepted for publication in ApJS

References in corpus (12)

• Cold Dark Clouds: The Initial Conditions for Star Formation
• A Minimum Column Density of 1 g cm^-2 for Massive Star Formation
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• CO Isotopologues in the Perseus Molecular Cloud Complex: the X-Factor and Regional Variations
• The relation between gas and dust in the Taurus Molecular Cloud
• The Milky Way Imaging Scroll Painting (MWISP): Project Details and Initial Results from the Galactic Longitude of 25.8deg to 49.7deg
• High abundance ratio of ${}^{13}$CO to C${}^{18}$O toward photon-dominated regions in the Orion-A giant molecular cloud
• A Possible Extension of the Scutum-Centaurus Arm into the Outer Second Quadrant
• Distances and statistics of local molecular clouds in the first Galactic quadrant
• The Forgotten Quadrant Survey. ${}^{12}$CO and ${}^{13}$CO (1-0) survey of the Galactic Plane in the range 220°$<l<$240° -2.5°$<b<$0°
• CO Outflow Candidates Toward the W3/4/5 Complex I: The Sample and its Spatial Distribution
• The segregation of starless and protostellar clumps in the Hi-GAL l=224deg region

Cited by in corpus (5)

• Molecular cloud catalogue from ${}^{13}$CO(1-0) data of the Forgotten Quadrant Survey
• Distributions and Physical Properties of Molecular Clouds in the Third Galactic Quadrant: $l$ = [219.75, 229.75]${}^{\circ }$ and $b$ = [-5.25, 5.25]${}^{\circ }$
• Investigating the Impact of Metallicity on Star Formation in the Outer Galaxy. I. VLT/KMOS Survey of Young Stellar Objects in Canis Major
• KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Discovery of parsec-scale CO depletion in the Canis Major star-forming region
• Examinations of CO completeness based on three independent CO surveys