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

Observations of six luminous blue compact galaxies (BCGs) and two star form ing companion galaxies were carried out with the CIGALE scanning Fabry-Pero t interferometer attached to the ESO 3.6 m telescope on La Silla. The obser vations were made in the H alpha emission line which is prominent in BCGs. A velocity sampling of 5 km s(-1) and a pixel size of 0.9 arcseconds were u sed. In this paper we present the observations and the data together with t he velocity fields and the derived rotation curves. In addition we provide rough estimates of the total dynamical mass and of the ionised gas mass for each galaxy. All galaxies display rotation, but while the companion galaxi es have regular velocity fields, those of the BCGs are complex and appear p erturbed. This is the most extensive study to date of the optical velocity fields of BCGs. The interpretation of these results will be presented in a forthcoming paper (Paper II).