This image is a portion of the all-sky survey from NASA’s Wide-field Infrared Survey Explorer, or WISE. It highlights the first of about 1,000 “hot DOGs” found by the mission (magenta circle). Hot DOGs are hot dust-obscured galaxies and are among the most powerful galaxies known. Yellow circles are active supermassive black holes found by WISE, which are much more common.
The panels at right show the “Hot DOG” as seen in the four individual infrared bands obtained by WISE. These images are at wavelengths from 5 to 30 times redder than what our eyes can see, with the shortest wavelengths at top, and longest at bottom.
Dust affects shorter wavelengths more than longer wavelengths. These objects are so dusty that not only their visible light but also their shorter-wavelength infrared light is blocked, as evident by their apparent absence in the top two panels. Less than one in 100,000 WISE sources are similarly prominent only in the two longer-wavelength WISE infrared bands.
Image credit: NASA/JPL-Caltech/UCLA