DISTORTION OF 2-5 μm IR BACKGROUND SPECTRUM FROM THE INVERSE COMPTON SCATTERING OF THE BACKGROUND PHOTONS ON A VERY HOT GAS IN A CLUSTER OF GALAXIES

Ⅰ. INTRODUCTION In 1983, Matsumoto et al. reported that they have detected a new IR background in the waveband 2-5 μm which has an approximately black body spectrum with a temperature ～1500 K. As is well known, the cosmic microwave background is the remainder of the hot Big Bang, then we must ask: Where does the IR background come from? In Ref. [2], B. J. Carr, et al. argued that either stars, or black