Close Neighbors of Markarian Galaxies. II. Statistics and Discussions
Résumé
According to the database from the first paper, we selected 180 pairs with dV < 800 km s-1 and Dp < 60 kpc containing Markarian (MRK) galaxies. We studied the dependence of galaxies' integral parameters, star-formation (SF), and active galactic nuclei (AGN) properties on kinematics of pairs, their structure, and large-scale environments. The following main results were obtained: projected radial separation Dp between galaxies correlates with the perturbation level P of the pairs. Both parameters do not correlate with line-of-sight velocity difference dV of galaxies. Dp and P are better measures of interaction strength than dV. The latter correlates with the density of large-scale environment and with the morphologies of galaxies. Both galaxies in a pair are of the same nature; the only difference is that MRK galaxies are usually brighter than their neighbors on average by 0.9 mag. Specific star formation rates (SSFR) of galaxies in pairs with smaller Dp or dV is on average 0.5 dex higher than that of galaxies in pairs with larger Dp or dV. Closeness of a neighbor with the same and later morphological type increases the SSFR, while earlier-type neighbors do not increase SSFR. Major interactions/mergers trigger SF and AGN more effectively than minor ones. The fraction of AGNs is higher in more perturbed pairs and pairs with smaller Dp. AGNs typically are in stronger interacting systems than star-forming and passive galaxies. There are correlations of both SSFRs and spectral properties of nuclei between pair members.