Spitzer and Hubble find 'Big Baby' galaxy in the early Universe
Left: The galaxy, named HUDF-JD2, was pinpointed among approximately 10 000 others in a small area of sky called the Hubble Ultra Deep Field (HUDF). This is the deepest image of the universe ever made at optical and near-infrared wavelengths.
Upper Right: A blow-up of one small area of the HUDF is used to identify where the distant galaxy is located (inside green circle). This indicates that the galaxy's visible light has been absorbed by travelling billions of light-years through intervening hydrogen.
Centre Right: The galaxy was detected using Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS). But at near-infrared wavelengths it is very faint and red.
Bottom Right: The Spitzer Infrared Array Camera (IRAC), easily detects the galaxy at longer infrared wavelengths. Spitzer's IRAC is sensitive to the light from older, redder stars, which should make up most of the mass in a galaxy. The brightness of the infrared galaxy suggests that it is quite massive.