Stars, HII regions, and shocked gas in the bar of NGC 1530

We analyse long slit spectra taken along and perpendicular to the bar of th e galaxy NGC 1530. Our data show that the H II regions, around young massiv e stars that form in the shock-compressed gas, share the same kinematics as the molecular gas in the x(2) orbits at the center of the galaxy. Along th e bar, the H II regions are in the post-shock zone, downstream of the dust lanes that contain molecular gas. Outside of the H II regions in the bar is faint, diffuse, ionized gas with a low H alpha/[NII] and H alpha/[SII] lin e ratio, which confirms the presence of shocks in the bar and supports a sh ock origin of the dust lanes. The measured spatial variation of the Ha and [NII] line intensity is consistent with the distribution of molecular gas a long the dust lanes and its high concentration near the first inner Lindbla d resonance. From an I - B image, we derive the surface brightness along th e bar which we interpret as the stellar distribution. We use these data to estimate the mass in the various structural components of the bar. The mass of the stars and gas in the bar is 4 x 10(10) M., or 12% of the total mass of the galaxy.