# Conversion factors for flux

I have a flux value in the infrared band of 8 mJy at a wavelength of 80 microns that I want to translate into X-ray conventional flux of keV/cm^2/s/keV. I have tried many conversion factors but none of them is helpful (see e.g. https://hea-www.harvard.edu/~pgreen/figs/Conversions.pdf). This table for example gives a conversion factor of $$10^{-26}$$ from mJy to erg/cm^2/s/Hz, and this is correct. However, when I go from erg/cm^2/s/Hz to keV/cm^2/s/keV, an additional $$10^{26}$$ factor comes out from the transformation of ergs and Hz. This cancels out with the previous factor and an unbelievable IR flux results, higher than the actually measured X-ray flux.

I know that the IR flux is much less than the X-ray flux, but can not find an appropriate way to convert.

• It depends on the object emitting the radiation, no? For example, a lightbulb will emit most of its energy in the infrared, with some visible light, whereas a medical X-ray tube will emit most of its energy in the X-ray band and basically none at other wavelengths. – Pierre Paquette Nov 28 '20 at 0:32