Gas Kinematics in the Magellanic-Type Galaxy NGC 7292

TL;DR

This study investigates the ionized gas kinematics in NGC 7292, revealing the true kinematic center, the influence of the bar and star formation, and potential interactions with a dwarf companion or gaseous cloud.

Contribution

It provides detailed kinematic analysis of NGC 7292 using new observations, identifying the true kinematic center and the effects of the bar and external interactions.

Findings

Kinematic center located at the bar's center, northwest of the photometric center.

Radial motions due to the bar significantly influence disk kinematics.

Perturbations from star formation are comparable to those caused by the bar.

Abstract

The paper presents results of studying the kinematics of the ionized gas in the galaxy of the Large Magellanic Cloud type NGC 7292 obtained with the 2.5-m telescope of the Caucasian Mountain Observatory (CMO SAI MSU) and the 6-m BTA telescope of the Special Astrophysical Observatory (SAO RAS). Analysis of the velocity fields of the ionized and neutral hydrogen showed that the kinematic center of NGC 7292 located at the center of the bar, northwest of the photometric center of the galaxy (the southeastern end of the bar) previously taken as the center of NGC 7292. In addition to the circular rotation of the gas, the radial motions associated with the bar play a significant role in the kinematics of the disk. The observed perturbations of the gaseous-disk kinematics induced by the ongoing star formation do not exceed those caused by the bar. It is possible that part of the non-circular motions (at the southeastern end of the bar which is the brightest HII region) may be related to the effects of the capture of a dwarf companion or a gaseous cloud.