  (abridged) Luminous blue compact galaxies are among the most active galaxies
in the local universe in terms of their star formation rate per unit mass. They
may be seen as the local analogs of higher redshift Lyman Break Galaxies.
Studies of their kinematics is key to understanding what triggers their
unusually active star formation In this work we investigate the kinematics of
stars and ionised gas in Haro11, one of the most luminous blue compact galaxies
in the local universe. Previous works have indicated that many such galaxies
may be triggered by galaxy mergers. We have employed Fabry-Perot
interferometry, long-slit spectroscopy and Integral Field Unit (IFU)
spectroscopy to explore the kinematics of Haro11. We target the near infrared
Calcium triplet to derive the stellar velocity field and velocity dispersion.
Ionised gas is analysed through emission lines from hydrogen, [OIII] , and
[SIII]. When spectral resolution and signal to noise allows we investigate the
the line profile in detail and identify multiple velocity components when
present. We find that to first order, the velocity field and velocity
dispersions derived from stars and ionised gas agree. Hence the complexities
reveal real dynamical disturbances providing further evidence for a merger in
Haro11. Through decomposition of emission lines we find evidence for
kinematically distinct components, for instance a tidal arm behind the galaxy.
The ionised gas velocity field can be traced to large galactocentric radii, and
shows significant velocity dispersion even far out in the halo. We discuss the
origin of the line width, and interpreted as virial motions it indicates a mass
of ~1E11 M_sun. Morphologically and kinematically Haro11 shows many
resemblances with the famous Antennae galaxies, but is much denser which is the
likely explanation for the higher star formation efficiency in Haro11.
