Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer

摘要

We present observations of the nearby barred starburst galaxy, M83 (NGC5236),with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter WilliamHerschel Telescope on La Palma. The unprecedented high resolution observations,of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of thegalaxy. The velocity field displays the dominant disk rotation with signaturesof gas inflow from kpc scales down to the nuclear regions. At the inner InnerLindblad Resonance radius of the main bar and centerd at the dynamical centerof the main galaxy disk, a nuclear $5.5 (\pm 0.9) \times 10^8 M_\odot$ rapidlyrotating disk with scale length of $60 \pm 20$ pc has formed. The nuclearstarburst is found in the vicinity as well as inside this nuclear disk, and ourobservations confirm that gas spirals in from the outer parts to feed thenuclear starburst, giving rise to several star formation events at differentepochs, within the central 100 pc radius of M83.