Abstract

We present GMRT 1280 MHz radio observations of a sample of twelve bulgeless spiral galaxies. These galaxies are late type spirals that appear to have no bulge or a very minimal bulge at their center. They are poorly evolved systems with gas rich disks that are often featureless and shrouded in dust. We have detected radio emission from five galaxies in the sample; the emission is mainly associated with disk star formation. For three of the detected galaxies the emission is weak and arises due to localized disk star formation. However, for the other two detections, the emission is relatively strong and extended; both galaxies are closely interacting with nearby companion galaxies and show signs of disk evolution such as spiral arms and weak bar distortions. Our study thus suggests that bulgeless galaxies are generally poor in star formation unless they are interacting with nearby galaxies. Interactions lead to an accelerated rate of disk evolution which may contribute to the buildup of bulges in these galaxies.