National Astronomical Observatory of Japan

Ultra Bright Submillimeter Galaxy “Orochi”

| Science

Multi-wavelength images of Orochi.
Multi-wavelength images of Orochi. Orochi is located at the center of each image. The bright sources on radio, millimeter and submillimeter wavelength images thought to be Orochi. On the other hands, the source at the center of optical and near-, mid-infrared images thought to be the foreground source.

An international team discovered an ultra bright submillimeter galaxy in the Subaru/XMM-Newton Deep Field by using a submillimeter telescope, ASTE operated by mainly National Astronomical Observatory of Japan (NAOJ) and University of Tokyo. This galaxy is more than 10 times brighter than usual submillimeter bright galaxies. Naming this source after a monster in a Japanese old legend, we nicknamed this source “Orochi”.

The research team observed Orochi by other instruments such as the Submillimeter Array in Hawaii, the Combined Array for Research in Millimeter-wave Astronomy in California, and the Caltech Submillimeter Observatory in Hawaii. Combining existing data taken by the Spitzer Space Telescope, the Very Large Array, the United Kingdom Infrared Telescope and the Subaru Telescope, the team revealed that Orochi was detected on all of these multi-wavelength data from optical to radio. The detailed analysis of these data indicates that some of the bright submillimeter flux from Orochi is probably gravitationally lensed by a foreground galaxy.