DR. ARUNIMA BANERJEE

We obtain mass models for three superthin galaxies using high resolution rotation curves obtained from HI 21 cm radiosynthesis observations and test for pseudo-isothermal (PIS) and Navarro-Frenk-White (NFW) density profiles of the dark matter halo. We find that while the PIS and the NFW density profiles fit the observed rotation curves of IC5249 and UGC7321 equally well, the NFW profile fails in case of IC2233. More interestingly, for all the PIS halo models, the best-fit case corresponds to a compact dark matter halo with Rc /RD < 1.5 where Rc is the core radius of the pseudo-isothermal halo and RD the exponential stellar disc scale length. Our results may have important implications for formation and evolution models of bulgeless galaxies in the universe.