The nature of the dense core population in the pipe nebula: core and cloud kinematics from C18O observations

Abstract

We present molecular-line observations of 94 dark cloud cores identified in the Pipe nebula through near-IR extinction mapping. Using the Arizona Radio Observatory 12m telescope, we obtained spectra of these cores in the J=1-0 transition of C18O. We use the measured core parameters, i.e., antenna temperature, linewidth, radial velocity, radius and mass, to explore the internal kinematics of these cores as well as their radial motions through the larger molecular cloud. We find that the vast majority of the dark extinction cores are true cloud cores rather than the superposition of unrelated filaments. While we identify no significant correlations between the core's internal gas motions and the cores' other physical parameters, we identify spatially correlated radial velocity variations that outline two main kinematic components of the cloud. The largest is a 15pc long filament that is surprisingly narrow both in spatial dimensions and in radial velocity. Beginning in the Stem of the Pipe, this filament displays uniformly small C18O linewidths (dv~0.4kms-1) as well as core to core motions only slightly in excess of the gas sound speed. The second component outlines what appears to be part of a large (2pc; 1000 solar mass) ring-like structure. Cores associated with this component display both larger linewidths and core to core motions than in the main cloud. The Pipe Molecular Ring may represent a primordial structure related to the formation of this cloud.

arXiv commentAccepted to ApJ. 14 pages, 11 figures. Complete table at end of document

References in corpus (8)

• The mass function of dense molecular cores and the origin of the IMF
• Mapping the interstellar dust with near-infrared observations: An optimized multi-band technique
• A Survey for Infall Motions toward Starless Cores. II. $CS(2-1)$ and $N_2{H}^{+}(1-0)$ Mapping Observations
• A Catalogue of Optically Selected Cores
• 2MASS wide field extinction maps - I. The Pipe nebula
• A Survey for Infall Motions toward Starless Cores. I. CS (2-1) and N${}_2$H${}^{+}$ (1-0) Observations
• The Spitzer c2d Survey of Nearby Dense Cores: IV. Revealing the Embedded Cluster in B59
• Structure Function Scaling of a 2MASS Extinction Map of Taurus

Cited by in corpus (42)

• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• A Correlation Between Surface Densities of Young Stellar Objects and Gas in Eight Nearby Molecular Clouds
• The "True" Column Density Distribution in Star-Forming Molecular Clouds
• Magnetically Regulated Star Formation in 3D: The Case of Taurus Molecular Cloud Complex
• Optical polarimetry toward the Pipe nebula: Revealing the importance of the magnetic field
• Dense Cores in Perseus: The Influence of Stellar Content and Cluster Environment
• Detailed Interstellar Polarimetric Properties of the Pipe Nebula at Core Scales
• The Age, Stellar Content and Star Formation Timescale of the B59 Dense Core
• Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula
• Dense cores in the Pipe Nebula: An improved core mass function
• Detection of Structure in Infrared-Dark Clouds with Spitzer: Characterizing Star Formation in the Molecular Ring
• The nature of the dense core population in the Pipe Nebula: A survey of NH3, CCS, and HC5N molecular line emission
• The Kinematics of Molecular Cloud Cores in the Presence of Driven and Decaying Turbulence: Comparisons with Observations
• Young starless cores embedded in the magnetically dominated Pipe Nebula
• Deep Near-Infrared Survey of the Pipe Nebula II: Data, Methods, and Dust Extinction Maps
• Do Lognormal Column-Density Distributions in Molecular Clouds Imply Supersonic Turbulence?
• Nonlinear Evolution of Gravitational Fragmentation Regulated by Magnetic Fields and Ambipolar Diffusion
• High Resolution Near-Infrared Survey of the Pipe Nebula I: A Deep Infrared Extinction Map of Barnard 59
• The molecular gas content of the Pipe Nebula I. Direct evidence of outflow-generated turbulence in B59?
• The mid-infrared extinction law in the darkest cores of the Pipe Nebula
• The BLAST Survey of the Vela Molecular Cloud: Physical Properties of the Dense Cores in Vela-D
• Distortion of Magnetic Fields in a Starless Core: Near-Infrared Polarimetry of FeSt 1-457
• Nothing to hide: An X-ray survey for young stellar objects in the Pipe Nebula
• Formation of dense structures induced by filament collisions. Correlation of density, kinematics and magnetic field in the Pipe nebula
• Chemical Differentiation toward the Pipe Nebula Starless Cores
• Some like it cold: molecular emission and effective dust temperatures of dense cores in the Pipe Nebula
• Simultaneous evolution of the virial parameter and star formation rate in molecular clumps undergoing global hierarchical collapse
• The direction of outflows from filaments : constraints on core formation
• The star formation law in Galactic high-mass star-forming molecular clouds
• Not so different after all: Properties and Spatial Structure of Column Density Peaks in the Pipe and Orion A Clouds
• Distortion of Magnetic Fields in a Starless Core III: Polarization--Extinction Relationship in FeSt 1-457
• Protostars at Low Extinction in Orion A
• ATLASGAL -- Star forming efficiencies and the Galactic star formation rate
• Young starless cores embedded in the magnetically dominated Pipe Nebula. II. Extended dataset
• The first frost in the Pipe Nebula
• The role of theta Oph in the formation and evolution of the Pipe Nebula - is star formation ever isolated?
• Distortion of Magnetic Fields in a Starless Core V: Near-infrared and Submillimeter Polarization in FeSt 1-457
• The BLAST Survey of the Vela Molecular Cloud: Dynamical Properties of the Dense Cores in Vela-D
• Distortion of Magnetic Fields in the Dense Core CB81 (L1774, Pipe 42) in the Pipe Nebula
• A spectral line survey of the starless and proto-stellar cores detected by BLAST toward the Vela-D molecular cloud
• Understanding biases in measurements of molecular cloud kinematics using line emission
• Probing the physical and chemical structure of the CS core in LDN 673. Multitransitional and continuum observations