Occurrence Frequency of CO Outflows in Massive Protostellar Candidates

Abstract

We mapped 12 massive protostellar candidates in the CO J=2-1 line, which in combination with Zhang et al. (2005) completes an unbiased survey of outflows for all 48 sources with l>50^o in a sample of 101 massive protostellar candidates. We detected outflows in 10 sources, implying 88% occurrence frequency of outflows for the 48 sources. This supports the conclusion of previous studies that bipolar outflows are an integral component in the formation process of massive stars. The vast majority of the observed outflows are much more massive (>10~Mo) and energetic (>100~Mo~km/s) than outflows from low-mass protostars. They also have large mass outflow rates (>2x10^{-4}~Mo/yr), suggesting large (~1x10^{-4}~Mo/yr) accretion rates sufficient to overcome radiation pressure of the central massive protostars. We compared the frequency distribution of collimation factors of 40 massive outflows including those of this study with that of 36 low-mass outflows from the literature, and found NO significant difference between the two. All these results are consistent with the suggestion that massive stars form through accretion as do low-mass stars but with much higher accretion rates.

15 pages, 3 figures, Accepted by ApJ

References in corpus (12)

• The Formation of Massive Stars from Turbulent Cores
• On the Formation of Massive Stars
• High-Mass Proto-Stellar Candidates - II : Density structure from dust continuum and CS emission
• High-Mass Proto-Stellar Candidates - I : The Sample and Initial Results
• Massive molecular outflows
• On the formation of massive stars
• A study of high velocity molecular outflows with an up-to-date sample
• The Birth of High Mass Stars: Accretion and/or Mergers?
• IRAS 05358+3543: Multiple outflows at the earliest stages of massive star formation
• Exteremely High Velocity Outflows
• A Single Distance Sample of Molecular Outflows from High-Mass Young Stellar Objects
• Star Formation in Massive Protoclusters in the Monoceros OB1 Dark Cloud

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• Submillimeter Array Observations of NGC 2264-C: Molecular Outflows and Driving Sources
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