An IRAS Atlas of Dark Clouds
Session 16 -- Molecular Clouds
Display presentation, Wednesday, January 12, 9:30-6:45, Salons I/II Room (Crystal Gateway)

## [16.01] An IRAS Atlas of Dark Clouds

D.O.S. Wood (NRAO), P.C. Myers, H. Chen (CfA)

We present recent results from our effort to construct and Atlas of Dark Clouds based on the IRAS Sky Survey Atlas (ISSA). The clouds in this study cover a wide range of physical properties including visual extinction, size, mass, degree of isolation, homogeneity and morphology. From the 100$\mu$m and 60$\mu$m images of the ISSA, we calculate the 100$\mu$m optical depth of dust in the clouds. By comparison with $^{12}$CO and $^{13}$CO observations, we convert the dust optical depth images to column density of H$_{2}$. From the column density images, we locate the edges of dark clouds and the dense cores inside them. We have developed software tools which automatically catalog the clouds, characterize their structures and calculate their physical properties (size, mass, maximum optical depth, etc.). We find that dark 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 also analyze the kinds of stars that have formed within the clouds and we characterize the star formation efficiency of dark clouds as a function of various physical parameters.