Detection of the Cosmic Far-Infrared Background in the AKARI Deep Field South

Understand

We report the detection and measurement of the absolute brightness and spatial fluctuations of the cosmic infrared background (CIB) with the AKARI satellite.

• We have carried out observations at 65, 90, 140 and 160 um as a cosmological survey in AKARI Deep Field South (ADF-S), which is one of the lowest cirrus regions with contiguous area on the sky.
• After removing bright galaxies and subtracting zodiacal and Galactic foregrounds from the measured sky brightness, we have successfully measured the CIB brightness and its fluctuations across a wide range of angular scales from arcminutes to degrees.
• The measured CIB brightness is consistent with previous results reported from COBE data but significantly higher than the lower limits at 70 and 160 um obtained with the Spitzer satellite from the stacking analysis of 24-um selected sources.