Ionized gas kinematics and massive star formation in NGC 1530

• DOI: 10.1051/0004-6361:20031049
• Publication Date: 2003-12-17T08:54:38Z
• Authors: A. Zurita; M. Relaño; J. E. Beckman; J. H. Knapen
• Keywords: Velocity gradient; Radial velocity; Velocity dispersion

We present emission line mapping of the strongly barred galaxy NGC 1530 obtained using Fabry-Pérot interferometry in Hα, at significantly enhanced angular resolution compared with previously published studies. The main point work is to examine detail non-circular components velocity field gas, presumably induced by non-axisymmetric gravitational potential bar. To do this we first derive a model rotation curve making minimum assumptions about kinematic symmetry, and go on measure component full radial field. This clearly reveals streaming motions associated spiral density wave producing arms, quasi-elliptical speeds order 100 km s-1 aligned It also shows some how these flows swing towards around nucleus as they cross circumnuclear resonance, from dominant "x1 orbits" outside resonance "x2 within it. Comparing cross-sections residual map along across bar surface brightness Hα indicates systematic offset between regions high massive star formation. investigate further produce maps gradient These illustrate very nicely shear compression revealed location dust lanes loci maximum perpendicular They show shear, seen our data flow, acts inhibit formation, whereas shocks, strong gradients flow vector, act enhance Although inhibiting effect gas formation has long been predicted, clearest observational illustration so far effect, thanks shock-induced counterflow system evidence that picks out inflow bars. observations should be considerable interest those modelling general.