1995A&A...295..585S

The barred spiral Seyfert galaxy NGC 1365 has been observed in the radio continuum at wavelengths of 20, 6 and 2cm using the VLA. Maps at 20 and 6cm with synthesized beams of about 2.3"x1.0" have been produced. The 2-cm maps have resolutions of 0.25"x0.10" and 2.36"x0.95". Spectral index maps are also presented. A 5" radio jet, with a steep spectral index (-0.9), seems to be emanating from the Seyfert nucleus in a southeastern direction along the apparent minor axis of the galaxy. The radio jet is aligned with the axis of a conical shell of hot ionized gas in accelerated outflow seen in the [OIII] emission line. A circumnuclear radio ring, containing the previously known non-thermal radio sources, has angular dimensions of 8"x20" with a major axis position angle of 30deg. Three of the radio sources are of similar character having a rather flat non-thermal spectrum (0 to -0.4) and contain components still unresolved with a linear resolution of the order of 10pc. The Seyfert nucleus has been detected as a weak radio source with a spectral index of -0.9. Extended radio emission has also been detected along the bar near the prominent dust lanes, where large-scale galactic shocks have been shown to be present. The molecular gas has been observed in the J=1-0 and 2-1 emission lines of the 2CO molecule using the SEST. The J=1-0 CO emission line was mapped with a 20"-grid spacing over a 120"x160" region centred on the nucleus, and the J=2-1 CO emission line was mapped in this region with a grid spacing of 10". The CO molecular gas is strongly concentrated to the nucleus, where the CO integrated line intensity has a maximum, and the CO distribution is aligned with the dust lanes along the bar. The (2-1)/(1-0)CO T_mb-ratio has a value of about 0.7 at the core of the northeastern dust complex about 10" from the nucleus, elsewhere this ratio is closer to 0.9. Weak CO emission has been detected in one spiral-arm region. The total molecular hydrogen gas mass in the observed region is 20x10⁹M_☉, with 6.3x10⁹M_☉ lying within a projected distance of 2.2kpc from the nucleus.