A comparison of density structures of a star forming and a non-star-forming globule. DCld303.8-14.2 and Thumbprint Nebula

Abstract

We present a study of radial density structure of the star forming globule, DCld303.8-14.2 (DC303), and a non-star forming globule, Thumbprint Nebula (TPN), using near-infrared data taken with the ISAAC instrument on the Very Large Telescope. We derive the extinction through the globules using the color excess technique and examine the radial density distribution using Bonnor-Ebert and power-law models. The two globules have significantly different density structures. The extinction profile of DC303 is best fitted with a single power-law with an exponent p = 2.29 \pm 0.08. An unstable Bonnor-Ebert model with a dimensionless parameter ξ_max = 23 \pm 3 provides equally good fit to data. The extinction profile of TPN flattens at small radii, making the profile significantly different from the profile of DC303. We are unable to fit the Bonnor-Ebert model for TPN in a robust manner, but derive the lower limit ξ_max > 8 for the dimensionless outer edge. The density profile derived for TPN is typical compared to recently observed pre-protostellar globules, with high ξ_max value which could be interpreted as the presence of significant additional support or very slow contraction.

arXiv comment10 pages, 12 figures, Accepted for publication in A&A

References in corpus (19)

• Tracing the Mass during Low-Mass Star Formation. II. Modelling the Submillimeter Emission from Pre-Protostellar Cores
• A Search for Infall Motions Toward Nearby Young Stellar Objects
• Tracing the Mass during Low-Mass Star Formation. I. Submillimeter Continuum Observations
• A Catalogue of Optically Selected Cores
• The initial conditions of isolated star formation - VI. SCUBA mapping of prestellar cores
• Molecular Evolution in Collapsing Prestellar Cores III: Contraction of A Bonnor-Ebert Sphere
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• Near Infrared Imaging Survey of Bok Globules: Density Structure
• The structure of protostellar envelopes derived from submillimeter continuum images
• Dynamic cores in hydrostatic disguise
• Cloudshine: New Light on Dark Clouds
• Large Area Mapping at 850 Microns. IV. Analysis of the Clump Distribution in the Orion B South Molecular Cloud
• Structure of Protostellar Collapse Candidate B335 Derived from Near-Infrared Extinction Maps
• Deep Near-Infrared Observations of L1014: Revealing the nature of the core and its embedded source
• Line profiles of molecular ions toward the pre-stellar core LDN 1544
• Envelope Structure of Starless Core L694-2 Derived from a Near-Infrared Extinction Map
• High-resolution mapping of interstellar clouds with near-infrared scattered light
• High Resolution Mapping of Interstellar Clouds by Near--IR Scattering
• Centimetre continuum emission from young stellar objects in Cederblad 110

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• Mass reservoirs surrounding massive infrared dark clouds: A view by near-infrared dust extinction
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• A 2MASS Analysis of the Stability of Southern Bok Globules
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