A new catalog of infrared dark clouds

Infrared dark clouds (IRDCs) are dark patches of cold dust and gas seen in the sky against the bright diffuse infrared glow of warm dust in our galaxy.

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Tau.Neutrino said:

A new catalog of infrared dark clouds

Infrared dark clouds (IRDCs) are dark patches of cold dust and gas seen in the sky against the bright diffuse infrared glow of warm dust in our galaxy.

more…

> the IRAC camera on Spitzer revolutionized the field with its dramatically enhanced sensitivity and spatial resolution. IRAC had completed several surveys of the Milky Way before being shut off last February, and astronomers have been using the infrared images to identify and analyze the characteristics of IRDCs. The Submillimeter Array and ALMA facilities, operating with high sensitivity and resolution at submillimeter wavelengths where the cold molecular gas can be characterized, have enabled astronomers to follow up on these newly discovered sources and to determine the gas temperatures, densities and motions, leading to advances in our understanding of the earliest stages of star formation in these stellar nurseries.

> One issue constraining research has been the lack of an up-to-date catalog of IRDCs. Sizes can vary greatly, shapes are irregular and ill defined, and they often are located in complex regions with hundreds of other sources.

> have just completed a new catalog of IRDCs containing 18,845 objects extracted from the IRAC infrared images.

Hold on. Spitzer is hardly a survey instrument, too narrow a field of view for that. So is this catalog going to be wildly incomplete? Or are the IR clouds confined to relatively small patches of sky that are bright IR sources which have all been imaged by Spirzer? Perhaps a bit of both?