I can't understand the question. But the spectrum of a hot object is not a bell curve. Specifically, there is a sharp cut-off such that there are basically no

I can't understand the question. But the spectrum of a hot object is not a bell curve. Specifically, there is a sharp cut-off such that there are basically no photons with wavelength below the cut-off. An incandescent light bulb of the type people used in houses in the 1980s and before for example produces a very small amount of UVA, but basically no UVB, UVC, x-rays or lower wavelengths.