Clues on the obscured active nucleus of NGC 1365

We have analyzed optical spectra (ESO-CASPEC) from the composite starburst- Seyfert galaxy NGC 1365 taken on the nucleus and the following positions (r elative to nucleus): 2 " N, 2 " W; 2 " S; 4 " S; 5 " S; 10 " S and 20 " W. A nuclear broad-line component indicative of the AGN source is confirmed in H beta and H alpha. Narrow-line widths vary between 150 and 200 km s(-1). Extranuclear line ratios in the observed regions are mostly consistent with the lines being formed in HII regions. One of the exceptions is a rise of [OIII]lambda 5007/H beta from 0.5 to 5 within 5 " (from west to east) acros s the nucleus suggesting the transition from gas ionized by stars to gas io nized by the active nucleus. Faint emission-line gas observed 20 " W of the nucleus (called region II) s hows line ratios lying in the AGN part of diagnostic diagrams. While at fir st glance shocks by bar streaming motions appear to be a suggestive explana tion for these line ratios we stress that there is no positive evidence for the velocities > 300 km s(-1) required for this mechanism. Another, presen tly more likely, explanation is that region II belongs to the far cone of t he bipolar nuclear outflow which can be glimpsed through the dusty disk. Ph otoionization of a single-density cloud system by a diluted AGN continuum r eproduces the measured line ratios, but leads via the ionization parameter to an intrinsic H alpha luminosity of the obscured AGN of similar to 10(42) erg s(-1) of which less than similar to 4% are observed in the central few arcseconds. Dust obscuration could explain H alpha but its concomitant gas column cannot account for the lack of Seyfert-1 typical hard X-rays from t he nucleus.