0220032

We propose to compare and contrast the broadband gamma ray spectrum of two carefully chosen Seyfert 1 galaxies with INTEGRAL MCG-2-58-22 and NGC3516 with a view to obtaining a better understanding of the intrinsic high-energy radiation from the central engine. The former object belongs to the Piccinotti sample of galaxies and is bright enough to be easily detectable by JEMX IBIS-ISGRI and SPI over this energy range. BATSE and OSSE have in fact detected it at high energies at a flux level of ~1E-10 erg cm-2 s-1 in the 20-100 keV range. This object has all the hallmarks of an unobscured nucleus. NGC3516 exhibits the characteristics of a bare Seyfert 1 nucleus that intermittently suffers the effects of transient absorption possibly caused by the passage of gas clouds across the line of sight. This object will also be clearly visible with INTEGRAL. We choose MCG-2-58-2 as our prime target because previous X-ray observations indicate that this source is the best-known candidate for a bare Seyfert 1 nucleus (i.e. a nucleus without spectral complexity). Furthermore the source spectrum is flatter than the cannonical 1.9 indicating that a distribution of power law indices in Seyfert galaxies is possible. The NGC3516 emission is likewise readily detectable by JEMX and IBIS-ISGRI and by SPI. We wish to observe it on two separate occassions. It has a hard power law emission at higher energies with significant energy dependent modulation around 10 keV. Comparing and contrasting the three measurements allows (1) testing and constraining X-ray production models for an unobscured central Seyfert 1 engine. (2) Evaluation of the effect of nearby clouds on this emission and (3) to better define the framework of the unified theory by assessing what a bare active nucleus and its local environment should look like. [truncated! Please see actual data for full text]