# Blackbody curves at low temperature

There is already a post here concerning a blackbody curve in visible light. The answer was helpful in that it stated that an object emitting visible light would emit some higher energy photons in x-ray and gamma.

But, what about a cold object at 288K (OC)? Does such a cold object also radiate x-ray and gamma? If so, how does it generate internal energy to produce those?

This is all in relation to hypothetical black bodies. Does all this apply to real objects?

• Technically, there is a probability of emitting a photon with pretty much any energy, but it can be quite low. I would expect a 288K body emits negligibly any gamma or x-ray, although it could in principle. As for the internal energy, it does not produce it, it has it. Its temperature means it has internal energy and it's radiating it with photon, that's the principle in the first place. Finally, it does apply to any object in equilibrium. – gingras.ol Aug 1 at 15:29
• It's worth working out how many photons of a given wavelength a black body at a given temperature should be expected to emit. I did this for $500\,\mathrm{keV}$ photons, for a body at $288\,\mathrm{K}$. I may have got this wrong, but I get about $8\times 10^{-8749553}\,\mathrm{m^{-2}}$ ... in the age of the universe: the chance of such a photon ever having being emitted is essentially zero. This is a computation you can't even do with floating point! – tfb Aug 1 at 19:59