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Author Omar, A. ♦ Dwarakanath, K. S.
Source Aryabhatta Research Institute of Observational Sciences (ARIES)
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Galaxy ♦ Evolution-Galaxies ♦ Clusters ♦ Eridanus-Radio Lines ♦ HI 21cm-line.
Abstract The HI content of galaxies in the Eridanus group is studied using the GMRT observations and the HIPASS data. A significant HI deficiency up to a factor of 2–3 is observed in galaxies in the high galaxy density regions. The HI deficiency in galaxies is observed to be directly correlated to the local projected galaxy density, and inversely correlated to the lineof- sight radial velocity. Furthermore, galaxies with larger optical diametersare predominantly in the lower galaxy density regions. It is suggested that the HI deficiency in Eridanus is due to tidal interactions. In some galaxies,evidences of tidal interactions are seen. An important implication is thatsignificant evolution of galaxies can take place in the group environment.In the hierarchical way of formation of clusters via mergers of groups, afraction of the observed HI deficiency in clusters could have originated ingroups. The co-existence of S0s and severely HI deficient galaxies in theEridanus group suggests that tidal interaction is likely to be an effectivemechanism for transforming spirals to S0s.
Part of series jaa26-71
Educational Use Research
Education Level UG and PG
Learning Resource Type Article