Optical and CO Radio Observations of Poor Cluster Zwicky 1615.8+3505

The cluster Zwicky 1615.8+3505 is considered to be a dynamically young poorcluster. To investigate the morphology and star-formation activity of galaxiesunder the environment of a dynamically young poor cluster, we have performed V,R, and I surface photometry, optical low-resolution spectroscopy, and 12CO(J=1-0) line observations for member galaxies. Our data show that more than 90%of the observed galaxies show regular morphologies and no star-formationactivities, indicating that the environment does not affect these galaxyproperties. Among sixteen galaxies observed, only NGC 6104 shows a significantstar-formation activity, and shows a distorted morphology, indicating a tidalinteraction. This galaxy contains double knots, and only one knot possessesSeyfert activity, though the sizes and luminosities are similar to each other;we also discuss this feature.Comment: LaTeX manuscript (text.tex, use PASJ style files), four PS figures (fig[a-d].ps), and three PASJ style files. text.tex, figb.ps, and figd.ps are up-dated. To be appeared in The Publications of the Astronomical Society of Japan, Vol. 51, No. 3 (1999 June issue