Modelling the gas kinematics of an atypical Lyman-alpha emitting compact
  dwarf galaxy
  Star-forming Compact Dwarf Galaxies (CDGs) resemble the expected pristine
conditions of the first galaxies in the Universe and are the best systems to
test models on primordial galaxy formation and evolution. Here we report on one
of such CDGs, Tololo 1214-277, which presents a broad, single peaked, highly
symmetric Ly$\alpha$ emission line that had evaded theoretical interpretation
so far. In this paper we reproduce for the first time these line features with
two different physically motivated kinematic models: an interstellar medium
composed by outflowing clumps with random motions and an homogeneous gaseous
sphere undergoing solid body rotation. The multiphase model requires a clump
velocity dispersion of $54.3\pm 0.6$ km s$^{-1}$ with outflows of $54.3\pm 5.1$
km s$^{-1}$, while the bulk rotation velocity is constrained to be
$348^{+75}_{-48}$ km s$^{-1}$. We argue that the results from the multiphase
model provide a correct interpretation of the data. In that case the clump
velocity dispersion implies a dynamical mass of $2\times 10^{9}$ M$_{\odot}$,
ten times its baryonic mass. If future kinematic maps of Tololo 1214-277
confirm the velocities suggested by the multiphase model, it would provide
additional support to expect such kinematic state in primordial galaxies,
opening the opportunity to use the models and methods presented in this paper
to constrain the physics of star formation and feedback in the early generation
of Ly-$\alpha$ emitting galaxies.
