Tracing the Evolution of Ultraluminous Infrared Galaxies into Radio
  Galaxies with Low Frequency Radio Observations
  We present radio observations of ultraluminous infrared galaxies (ULIRGs)
using the Giant Metrewave Radio Telescope (GMRT) and combine them with archival
multi-frequency observations to understand whether ULIRGs are the progenitors
of the powerful radio loud galaxies in the local Universe. ULIRGs are
characterized by large infrared luminosities ($L_{IR}>$10$^{12}$L$\odot$),
large dust masses ($\sim10^{8}M_{\odot}$) and vigorous star formation (star
formation rates $\sim$10-100 $M_{\odot}~$yr$^{-1}$). Studies show that they
represent the end stages of mergers of gas-rich spiral galaxies. Their
luminosity can be due to both starburst activity and active galactic nuclei
(AGN). We study a sample of 13 ULIRGs that have optically identified AGN
characteristics with 1.28~GHz GMRT observations. Our aim is to resolve any
core-jet structures or nuclear extensions and hence examine whether the ULIRGs
are evolving into radio loud ellipticals. Our deep, low frequency observations
show marginal extension for only one source. However, the integrated radio
spectra of 9 ULIRGs show characteristics that are similar to that of
GPS/CSS/CSO/young radio sources. The estimated spectral ages are 0.4 to 20 Myr
and indicate that they are young radio sources and possible progenitors of
radio galaxies. Hence, we conclude that although most ULIRGs do not show kpc
scale extended radio emission associated with nuclear activity, their radio
spectral energy distributions do show signatures of young radio galaxies.
