Molecular Gas and Star Formation in Voids
  We present the detection of molecular gas using CO(1-0) line emission and
follow up Halpha imaging observations of galaxies located in nearby voids. The
CO(1-0) observations were done using the 45m telescope of the Nobeyama Radio
Observatory (NRO) and the optical observations were done using the Himalayan
Chandra Telescope (HCT). Although void galaxies lie in the most under dense
parts of our universe, a significant fraction of them are gas rich, spiral
galaxies that show signatures of ongoing star formation. Not much is known
about their cold gas content or star formation properties. In this study we
searched for molecular gas in five void galaxies using the NRO. The galaxies
were selected based on their relatively higher IRAS fluxes or Halpha line
luminosities. CO(1--0) emission was detected in four galaxies and the derived
molecular gas masses lie between (1 - 8)E+9 Msun. The H$\alpha$ imaging
observations of three galaxies detected in CO emission indicates ongoing star
formation and the derived star formation rates vary between from 0.2 - 1.0
Msun/yr, which is similar to that observed in local galaxies. Our study shows
that although void galaxies reside in under dense regions, their disks may
contain molecular gas and have star formation rates similar to galaxies in
denser environments.
