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Kinematics and morphology of ionized gas in Hickson Compact Group 18

H. Plana·P. Amram·C. Mendes de Oliveira·C. Balkowski
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Abstract

We present new observations of $Hα$ 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 $Hα$ 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.

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H. Plana, P. Amram, C. Mendes de Oliveira, C. Balkowski. 2000-04-26. Kinematics and morphology of ionized gas in Hickson Compact Group 18. https://doi.org/10.1086/301506

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