1.3-mm observation

1.3-mm observation of electromagnetic radiation (EMR) is useful for detecting how much cold dust is somewhere. The wavelength is within an atmospheric window, and the black-body radiation of cold dust produces considerable 1.3-mm signal with sufficiently few other sources to make it useful for finding dust clouds and protoplanetary disks. Dust is optically thin at this wavelength so the signal corresponds to the mass of the dust cloud. The window allows observation of a number of molecular lines as well as the continuum at that wavelength. The Submillimeter Array (SMA) and other similar telescopes image and survey at this wavelength.