Kinematics and morphology of ionized gas in Hickson Compact Group 18

Abstract

We present new observations of $H\alpha$ emission in the Hickson Compact Group 18 (HCG 18) obtained with a scanning Fabry-Perot interferometer. The velocity field does not show motions of individual group members but, instead, a complex common velocity field for the whole group. The gas distribution is very asymmetric with clumps of maximum intensity coinciding with the optically brightest knots. Comparing $H\alpha$ and HI data we conclude that HCG 18 is not a compact group but instead a large irregular galaxy with several clumps of star formation.

Accepted for publication in Astronomical Journal (13p 6 figures)

References in corpus (5)

• Effects of Interaction Induced Activities in Hickson Compact Groups: CO and FIR Study
• On the Influence of the Environment in the Star Formation Rates of a Sample of Galaxies in Nearby Compact Groups
• Extented ionized gas emission and kinematics of the compact group galaxies in HCG 16: Signatures of mergers
• The kinematics of the warm gas in Hickson compact group of galaxies HCG 90
• H-Alpha Velocity Fields of H II Regions in Nearby Dwarf Irregular Galaxies

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