VLA HI Imaging of the Extreme Star-Forming Dwarf Galaxy Leo P
American Astronomical Society, AAS Meeting #221, #352.07
Published in Jan 2013
The ALFALFA survey recently discovered the galaxy Leo P, one of the most extreme low-mass star-forming dwarf galaxies in the local volume. We present new HI spectral line imaging of Leo P acquired with the Karl G. Jansky Very Large Array (VLA) in the B- and C-configurations. A peak column density of 2.5×1020 cm-2 is detected at 30 arcsecond resolution and is spatially coincident with the optical center. Diffuse, low column density HI emission extends to the Southeast. 40% of the ALFALFA flux was recovered by the C-configuration observations; a substantial fraction of the neutral gas component resides on scales larger than 30 arcseconds. A sparsely sampled rotation curve demonstrates that the neutral gas is kinematically complex on scales of ~100 pc. We estimate the dynamical mass Mdyn = 8×106 DMpc M☉, where DMpc is the distance in Mpc. This can be compared with the total HI mass, MHI = 3×105 D2Mpc .
(c) 2013: American Astronomical Society