A search for HI in some peculiar faint dwarf galaxies

Abstract

We present a deep Giant Metrewave Radio Telescope (GMRT) search for HI 21 cm emission from three dwarf galaxies, viz. POX 186, SC 24 and KKR 25. Based, in part, on previous single dish HI observations, these galaxies have been classified as a BCD, a dwarf irregular and a transition galaxy respectively. However, in conflict with previous single dish detections, we do not detect HI in SC 24 or KKR 25. We suggest that the previous single dish measurements were probably confused with the local galactic emission. In the case of POX 186, we confirm the previous non detection of HI but with substantially improved limits on its HI mass. Our derived upper limits on the HI mass of SC 24 and KKR 25 are similar to the typical HI mass limit for dwarf spheroidal galaxies, whereas in the case of POX 186, we find that its gas content is somewhat smaller than is typical of BCD galaxies.