@veron. Most part of the remaining 2722 galaxies lacks of information about nuclear spectrum or have spectra of HII regions (22 starburst spectra). They are not included in any AGN catalogue and for this reason in the following discussion we refer to them as “non active galaxies" and to the others as “active galaxies". With all these data, we crossed the various tracers to understand and revisit the main relations existing between X, FIR, CO and B luminosities.

Cold gas and warm dust
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The relations existing between different cold components of the ISM such as the molecular gas and the dust have been studied since many years [@mirabel; @solomon; @bregman]. They find that the global galaxy luminosity derived from CO(1-0) line is directly related with the flux at 100 $\mu$m. With our large sample we can now test these relations using galaxies of different morphological types and activity or interaction.

In Figure \[CO\_100\] we plotted the logarithm of the flux measured from CO(1-0) line vs. the logarithm of the IRAS flux at 100 $\mu$m. In our plots, we have 193 galaxies with classification from E to Sb and 178 from Sbc to Sm. The relation found by @bregman for 