NGC-4945 - THE BRIGHTEST SEYFERT-2 GALAXY AT 100 KEV

Seyfert 2 galaxies are generally heavily absorbed in soft X-rays, plau sibly because of obscuration of the Seyfert nucleus by a thick molecul ar torus. With a high torus column, 10(23) greater than or equal to N- H greater than or equal to 10(25) cm(-2), the observed flux in the ''c lassical'' 2-10 keV X-ray band can be strongly suppressed, while at hi gher energies the photoelectric absorption becomes less important and the true nuclear luminosity can be seen. The high-energy bandpass of t he Ginga X-ray telescope, extending to 20 keV, allowed several such ob jects to be discovered, and an extrapolation of the obscured nuclear s pectra out to 100 keV suggested that NGC 4945 should be among the very brightest radio-quiet Seyferts in the sky at 100 keV, second only to NGC 4151. OSSE data reported here confirm this prediction, and we anal yze these, together with archival Ginga and ASCA data, in order to pre sent a broadband spectrum from 0.6-500 keV of this object.