The Evolution of Luminous Compact Blue Galaxies: Disks or Spheroids?
  Luminous compact blue galaxies (LCBGs) are a diverse class of galaxies
characterized by high luminosities, blue colors, and high surface brightnesses.
Residing at the high luminosity, high mass end of the blue sequence, LCBGs sit
at the critical juncture of galaxies that are evolving from the blue to the red
sequence. Yet we do not understand what drives the evolution of LCBGs, nor how
they will evolve. Based on single-dish HI observations, we know that they have
a diverse range of properties. LCBGs are HI-rich with M(HI)=10^{9-10.5} M(sun),
have moderate M(dyn)=10^{10-12} M(sun), and 80% have gas depletion timescales
less than 3 Gyr. These properties are consistent with LCBGs evolving into
low-mass spirals or high mass dwarf ellipticals or dwarf irregulars. However,
LCBGs do not follow the Tully-Fisher relation, nor can most evolve onto it,
implying that many LCBGs are not smoothly rotating, virialized systems. GMRT
and VLA HI maps confirm this conclusion revealing signatures of recent
interactions and dynamically hot components in some local LCBGs, consistent
with the formation of a thick disk or spheroid. Such signatures and the high
incidence of close companions around LCBGs suggest that star formation in local
LCBGs is likely triggered by interactions. The dynamical masses and apparent
spheroid formation in LCBGs combined with previous results from optical
spectroscopy are consistent with virial heating being the primary mechanism for
quenching star formation in these galaxies.
