A search for H I in some peculiar faint dwarf galaxies

Abstract

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