An international joint research team consisting of Japan, UK, US, and Mexico 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 ultra bright submillimeter galaxy is more than 10 times brighter than usual submillimeter bright galaxies (SMGs). So we nicknamed this source “Orochi”. “Orochi” came from “Yamatano Orochi”, which was a monster in a Japanese old legend.

  We observed Orochi by using the Submillimeter Array (SMA) in Hawaii, the Combined Array for Research in Millimeter-wave Astronomy (CARMA) in California, and the Caltech Submillimeter Observatory (CSO) in Hawaii. We also used existing data of the Spitzer Space Telescope (SST), the Very Large Array (VLA), the United Kingdom Infrared Telescope (UKIRT) and the Subaru Telescope. These data revealed that Orochi was detected on all  of these multi-wavelength data from optical to radio (Fig. 1).  The detailed analysis of these data indicates that some of the bright submillimeter flux from Orochi is probably gravitationally lensed by  a foreground galaxy (Fig. 2).


  We plan further researches for Orochi in order to reveal its magnification factor and study starburst in the early universe.

Figure 1. 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.

Figure 2. When two galaxies at different distance from us located in the same eye direction, the flux from the back ground galaxy is probably magnified by the gravity of the foreground galaxy. Some flux of Orochi is thought to be lensed by the foreground galaxy.