Abstract Details

Name: Sushma Kurapati
Affiliation: Research Scholar
Conference ID: ASI2017_822
Title : HI observations of gas-rich void galaxies
Authors and Co-Authors : Jayaram N. Chengalur and NCRA-TIFR
Abstract Type : Oral
Abstract Category : Extragalactic astronomy
Abstract : Studying the void galaxies will allow us to understand the effect of environment on galaxy evolution, as the low density environment is expected to result in low rate of interactions and mergers. Numerical simulations indicate that fainter dwarfs (Magnitudes fainter than -16) in voids are significantly bluer and have higher specific star formation rates than their higher density counterparts, while the luminous dwarfs (M~ -18) in voids are statistically indistinguishable from similar dwarfs in the field. Previous observational studies show that, for brighter dwarfs (brighter than -16.5), the properties of void galaxies are statistically identical to their counterparts in dense regions. Since the effect of environment is expected to be the largest for the galaxies of the smallest masses, it is important to study the fainter dwarfs from nearby voids. The nearest void, Lynx-Cancer sample contains a total of 104 galaxies for which optical photometry, gas metallicity and HI integrated parameters are available. Some of the faint galaxies from this sample appear to evolve in average slower than their analogs in denser environments. A relatively small fraction (~10%) of void low mass galaxies show unusual properties indicating their unevolved status. We have selected the upper quartile of gas-rich galaxies (with M(HI)/L(B) >1.9) for a statistical robust analysis of the gas distribution, kinematics and dark matter distribution. This sample allows us to not only examine the global statistical properties of void galaxies, but also to explore the details of dynamical properties (e.g. signs of mergers, etc). We present the neutral hydrogen properties, i.e content, morphology and kinematics of these 28 galaxies in detail. We also highlight the key results on individually interesting systems.