Conclusions

We have presented a multiwaveband study of the Seyfert 1 galaxy MCG-6-30-15, including previously unpublished optical data from the AAT, and UV data from IUE. Our compilation of data, spanning 6 decades of frequency, has allowed us to examine reprocessing mechanisms and the geometry of this system.

The optical line and continuum emission both show the effects of dust extinction. The reddening inferred from Balmer line studies lies in the range E(B-V)=0.61-1.09. Given this reddening, we would expect the UV emission from the source to be less than observed. The fact that we do detect a UV continuum and broad CIV line can be reconciled with a typical Seyfert spectrum if 1-5 per cent of the intrinsic (i.e. dereddened) source spectrum is scattered around the matter responsible for the extinction and into our line of sight. UV spectropolarimetry will be required to test this hypothesis.

The X-ray spectrum of this Seyfert nucleus clearly reveals a warm absorber but little of the cold (neutral) absorption that would be expected to accompany the dust responsible for the optical/UV reddening. To reconcile the X-ray absorption with the optical reddening we postulate that the dust resides in the warm absorber. Detailed X-ray studies have shown the warm absorber to be comprised of at least two-zones - an inner warm absorber at distances characteristic of the BLR and an outer warm absorber at distances characteristic of the putative molecular torus. Dust cannot survive in the inner warm absorber due to the intense radiation field - thus, the dust must reside in the outer absorber. We have examined photoionization models of the dusty (outer) warm absorber. Upon comparing such models with ASCA spectra we find evidence for non-standard dust mixtures, although the current data to not allow us to pursue this issue in detail.

The optical spectrum of MCG-6-30-15 displays the high-excitation forbidden lines of [FeX] , [FeXI] and [FeXIV] , the so-called coronal lines. As is often found in other Seyfert nuclei, these lines have widths that are intermediate between those of the broad Balmer lines and the lower-excitation forbidden lines. Photoionization modeling with CLOUDY suggests that the CLR may be identified with the outer warm absorber.