EPoS Contribution

The Properties of A New Catalogue of Spitzer Infrared Dark Clouds Gary A. Fuller Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester, UK
To better characterise infrared dark clouds (IRDCs), and the star formation within them, a comprehensive catalogue of IRDCs has been constructed from the Spitzer GLIMPSE and MIPSGAL archival data. Mosaicing the individual survey blocks together, a new extraction method has been used to identify dark clouds up to 30' in size, producing a column density image of each cloud. In total the catalogue contains over 11,000 clouds, defined as connected regions with 8 micron optical depth >0.35 (corresponding to column densities >10^{22} cm^{-2} ). The extraction algorithm also identifies sub-structures (fragments) within each cloud. These Spitzer dark clouds (SDCs) range in mass from 10 M_sun to 10^4 M_sun. About 80% of the SDCs were previously unidentified. About 30% of the SDCs are associated with 24 micron point-like sources, leaving the majority of these clouds with no apparent sign of star formation activity. In this presentation I will discuss this catalogue and recent results on the properties of the clouds and their star formation.
Collaborators: N. Peretto, Manchester, UK and CEA/SAp Saclay, France	Key publication Suggested Session: Cores and Collapse, Massive Stars, Molecular Clouds