Photometric and spectroscopic study of the Shakhbazian compact galaxy groups ShCG 254, ShCG 257, ShCG 351, and ShCG 371

Abstract

Results of a detailed spectroscopic and photometric study of the four Shakhbazian compact galaxy groups ShCG 254, ShCG 257, ShCG 351, and ShCG 371 are reported. The redishifts of the member galaxies and radial velocity dispersions in these groups have been determined. The R surface brightness distributions of the member galaxies have been studied. The morphological types of the galaxies have been determined based on the profiles of the surface brightness, µ, as functions of the semimajor axis α1/4 or α. Some members of the groups are in the process of interacting. Curves of isophotal twisting and the Fourier parameter α4 have been plotted. The physical parameters of the groups (radial velocity dispersions, virial radii and masses, luminosities, mass-to-luminosity ratios, and crossing times) have also been derived.