Dynamics of Dense Cores in the Perseus Molecular Cloud

Abstract

We survey the kinematics of over one hundred and fifty candidate (and potentially star-forming) dense cores in the Perseus molecular cloud with pointed N2H+(1-0) and simultaneous C18O(2-1) observations. Our detection rate of N2H+ is 62%, rising to 84% for JCMT SCUBA-selected targets. In agreement with previous observations, we find that the dense N2H+ targets tend to display nearly thermal linewidths, particularly those which appear to be starless (using Spitzer data), indicating turbulent support on the small scales of molecular clouds is minimal. For those N2H+ targets which have an associated SCUBA dense core, we find their internal motions are more than sufficient to provide support against the gravitational force on the cores. Comparison of the N2H+ integrated intensity and SCUBA flux reveals fractional N2H+ abundances between 10^-10 and 10^-9. We demonstrate that the relative motion of the dense N2H+ gas and the surrounding C18O gas is less than the sound speed in the vast majority of cases (~90%). The point-to-point motions we observe within larger extinction regions appear to be insufficient to provide support against gravity, although we sparsely sample these regions.

49 pages, 20 figures. Accepted for publication in the Astrophysical Journal

References in corpus (8)

• The COMPLETE Survey of Star-Forming Regions: Phase I Data
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• Current Star Formation in the Perseus Molecular Cloud: Constraints from Unbiased Submillimeter and Mid-Infrared Surveys
• Large Area Mapping at 850 Microns. V. Analysis of the Clump Distribution in the Orion A South Molecular Cloud
• A Large Scale Survey of NGC1333
• SCUBA observations of the Horsehead Nebula - what did the horse swallow?
• Star formation in the vicinity of the IC 348 cluster
• On the relative motions of dense cores and envelopes in star-forming molecular clouds

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• Constraining the Earliest Circumstellar Disks and their Envelopes
• Molecular line profiles as diagnostics of protostellar collapse: modelling the `blue asymmetry' in inside-out infall
• The Interplay of Turbulence & Magnetic Fields in Star-Forming Regions: Simulations and Observations