Study of the structure and kinematics of the NGC 7465/64/63 triplet galaxies

TL;DR

This study analyzes new observational data of the NGC 7465/64/63 galaxy triplet, revealing complex structures, interactions, and kinematic features, including a polar ring, warped disks, and signs of gravitational interaction.

Contribution

It provides detailed kinematic and structural analysis of the galaxy triplet using new spectroscopic data, highlighting interactions and unique features of each galaxy.

Findings

NGC 7465 has an inner stellar disk and a warped gaseous disk.

NGC 7464 is an irregular galaxy affected by gravitational interaction.

NGC 7463 shows typical spiral galaxy velocity fields with signs of environmental influence.

Abstract

This paper is devoted to the analysis of new observational data for the group of galaxies NGC 7465/64/63, which were obtained at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) with the multimode instrument SCORPIO and the Multi Pupil Fiber Spectrograph. For one of group members (NGC 7465) the presence of a polar ring was suspected. Large-scale brightness distributions, velocity and velocity dispersion fields of the ionized gas for all three galaxies as well as line-of-sight velocity curves on the basis of emission and absorption lines and a stellar velocity field in the central region for NGC 7465 were constructed. As a result of the analysis of the obtained information, we revealed an inner stellar disk (r ~ 0.5 kpc) and a warped gaseous disk in addition to the main stellar disk, in NGC 7465. On the basis of the joint study of photometric and spectral data it was ascertained that NGC 7464 is the irregular galaxy of the IrrI type, whose structural and kinematic peculiarities resulted most likely from the gravitational interaction with NGC 7465. The velocity field of the ionized gas of NGC 7463 turned out typical for spiral galaxies with a bar, and the bending of outer parts of its disk could arise owing to the close encounter with one of galaxies of the environment.