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IRAS images of nearby dark cloudsWe have investigated approximately 100 nearby molecular clouds using the extensive, all-sky database of IRAS. The clouds in this study cover a wide range of physical properties including visual extinction, size, mass, degree of isolation, homogeneity and morphology. IRAS 100 and 60 micron co-added images were used to calculate the 100 micron optical depth of dust in the clouds. These images of dust optical depth compare very well with (12)CO and (13)CO observations, and can be related to H2 column density. From the optical depth images we locate the edges of dark clouds and the dense cores inside them. We have identified a total of 43 `IRAS clouds' (regions with A(sub v) greater than 2) which contain a total of 255 `IRAS cores' (regions with A(sub v) greater than 4) and we catalog their physical properties. We find that the clouds are remarkably filamentary, and that the cores within the clouds are often distributed along the filaments. The largest cores are usually connected to other large cores by filaments. We have developed selection criteria to search the IRAS Point Source Catalog for stars that are likely to be associated with the clouds and we catalog the IRAS sources in each cloud or core. Optically visible stars associated with the clouds have been identified from the Herbig and Bell catalog. From these data we characterize the physical properties of the clouds including their star-formation efficiency.
Document ID
19950041632
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Wood, Douglas O. S.
(National Radio Astronomy Observatory, Socorro, NM United States)
Myers, Philip C.
(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Daugherty, Debra A.
(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Date Acquired
August 16, 2013
Publication Date
December 1, 1994
Publication Information
Publication: Astrophysical Journal Supplement Series
Volume: 95
Issue: 2
ISSN: 0067-0049
Subject Category
Astronomy
Accession Number
95A73231
Funding Number(s)
CONTRACT_GRANT: NAGW-3401
Distribution Limits
Public
Copyright
Other

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