Mysterious Infrared Light from Space Resolved Perfectly

A research team using the Atacama Large Millimeter/submillimeter Array (ALMA) has detected the faintest millimeter-wave source ever observed. By accumulating millimeter-waves from faint objects like this throughout the Universe, the team finally determined that such objects are 100% responsible for the enigmatic infrared background light filling the Universe. By comparing these to optical and infrared images, the team found that 60% of them are faint galaxies, whereas the rest have no corresponding objects in optical/infrared wavelengths and their nature is still unknown.

These observational results were published as Fujimoto et al. “ALMA Census of Faint 1.2 mm Sources Down to ~ 0.02 mJy: Extragalactic Background Light and Dust-poor, High-z Galaxies" in the Astrophysical Journal Supplement, issued in December 28, 2015.

Artist’s impression of the Cosmic Infrared Background resolved with ALMA.
Artist’s impression of the Cosmic Infrared Background resolved with ALMA. Original size (5.11MB)

For details, see Press Release: Mysterious Infrared Light from Space Resolved Perfectly.

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