  We present an intrinsic AGN SED extending from the optical to the submm,
derived with a sample of unobscured, optically luminous (vLv(5100)>10^43.5
erg/s) QSOs at z<0.18 from the Palomar Green survey. The intrinsic AGN SED was
computed by removing the contribution from stars using the 11.3um polycyclic
aromatic hydrocarbon (PAH) feature in the QSOs' mid-IR spectra; the 1sigma
uncertainty on the SED ranges between 12 and 45 per cent as a function of
wavelength and is a combination of PAH flux measurement errors and the
uncertainties related to the conversion between PAH luminosity and star-forming
luminosity. Longwards of 20um the shape of the intrinsic AGN SED is independent
of the AGN power indicating that our template should be applicable to all
systems hosting luminous AGN (vLv(5100) or L_X(2-10keV) > 10^43.5 erg/s). We
note that for our sample of luminous QSOs, the average AGN emission is at least
as high as, and mostly higher than, the total stellar powered emission at all
wavelengths from the optical to the submm. This implies that in many galaxies
hosting powerful AGN, there is no `safe' broadband photometric observation (at
lambda<1000um) which can be used in calculating star-formation rates without
subtracting the AGN contribution. Roughly, the AGN contribution may be ignored
only if the intrinsic AGN luminosity at 5100 Ang is at least a factor of 4
smaller than the total infrared luminosity (L_IR; 8-1000um) of the galaxy.
Finally, we examine the implication of our work in statistical studies of
star-formation in AGN host galaxies.
