Dynamics of blue compact galaxies, as revealed by their H-alpha velocity fields I. The data, velocity fields and rotation curves

摘要

Observations of six luminous blue compact galaxies (BCGs) and two starforming companion galaxies were carried out with the CIGALE scanningFabry-Perot interferometer attached to the ESO 3.6m telescope on La Silla. Theobservations were made in the H-alpha emission line which is prominent in BCGs.A velocity sampling of 5 km/s and a pixel size of 0.9 arcseconds were used. Inthis paper we present the observations and the data together with the velocityfields and the derived rotation curves. In addition we provide rough estimatesof the total dynamical mass and of the ionised gas mass for each galaxy. Allgalaxies display rotation, but while the companion galaxies have regularvelocity fields, those of the BCGs are complex and appear perturbed. This isthe most extensive study to date of the optical velocity fields of BCGs. Theinterpretation of these results will be presented in a forthcoming paper (PaperII).