A Tentative Detection of the Cosmic Infrared Background at 3.5 microns Using COBE/DIRBE Observations

Abstract

Foreground emission and scattered light from interplanetary dust (IPD) particles and emission from Galactic stellar sources are the greatest obstacles for determining the cosmic infrared background (CIB) from diffuse sky measurements in the ~ 1 to 5 micron range. We describe a new method for deriving the CIB at near infrared wavelengths which reduces the uncertainties associated with the removal of the Galactic stellar emission component from the sky maps. The method produces positive residuals at 3.5 and 4.9 microns, of which only the 3.5 micron residual is nearly isotropic. We consider our result as a tentative detection of the CIB at this wavelength.