First results from SAM-FP: Fabry-Perot observations with ground-layer
  adaptive optics - the structure and kinematics of the core of 30 Doradus
  The aim of this paper is to present the first data set obtained with SOAR
Adaptive Module-Fabry-Parot (SAM-FP), a Fabry-Perot instrument mounted inside
the SOAR telescope Adaptive-Optics Module. This is the only existing imaging
Fabry-Perot interferometer using laser-assisted ground-layer adaptive optics.
SAM-FP was used to observe the ionized gas, traced by Halpha, in the centre of
the 30 Doradus starburst (the Tarantula Nebula) in the Large Magellanic Cloud,
with high spatial (~0.6" or 0.15 pc) and spectral (R=11200) resolution. Radial
velocity, velocity dispersion and monochromatic maps were derived. The region
displays a mix of narrow, sigma ~ 20 km/s profiles and multiple broader
profiles with sigma ~ 70-80 km/s, indicating the complex nature of the nebula
kinematics. A comparison with previously obtained VLT/FLAMES spectroscopy
demonstrates that the data agree well in the regions of overlap, but the
Fabry-Perot data are superior in spatial coverage. A preliminary analysis of
the observations finds a new expanding bubble south of R136, with a projected
radius of r=5.6 pc and an expansion velocity of 29 +/- 4 km/s. In addition, the
first-time detailed kinematic maps derived here for several complexes and
filaments of 30 Doradus allow identification of kinematically independent
structures. These data exemplify the power of the combination of a high-order
Fabry-Perot with a wide-field imager (3' x 3' GLAO-corrected field of view) for
high-resolution spatial and spectral studies. In particular, SAM-FP data cubes
are highly advantageous over multifibre or long-slit data sets for nebula
structure studies and to search for small-scale bubbles, given their greatly
improved spatial coverage. For reference, this paper also presents two
appendices with detailed descriptions of the usage of Fabry-Perot devices,
including formulae and explanations for understanding Fabry-Perot observations.
