NGC-1808 - ACTIVE GALACTIC NUCLEUS OR STARBURST

We present optical and near-infrared images, together with long-slit spectra at red wavelengths, of NGC 1808. The complex morphology of hotspots seen at short wavelengths may be the result of dust obscuration. Our data (namely the equivalent width of the Ca II triplet and broad-band colours) suggest the presence of red super-giants, associated with a burst of star formation less than 5 x 10(7) yr ago. NGC 1808 is claimed to show spectral evidence for weak Seyfert-like activity in the nucleus, surrounded by a circumnuclear starburst. Combining our data with those in the literature, we discuss the nature of the hotspots and nucleus. In particular, we show that the line ratios and widths in the nucleus are qualitatively consistent with those of a supernova remnant embedded within a high-abundance H II region. The [S II] doublet indicates a large electron density. We conclude that the radio properties of the nucleus and nuclear region can be explained by a few, albeit powerful, SNRs. A probable off-nucleus SNR, about 100 times more powerful than Cas A, is identified for further study. We claim that stellar and gaseous processes associated with the starburst can explain the 'activity' in the nuclear region of this galaxy without invoking a black hole.