A slow lopsided bar in the interacting dwarf galaxy IC 3167

TL;DR

This study analyzes the properties of a lopsided, slow-rotating bar in the dwarf galaxy IC 3167, suggesting its formation is driven by galaxy interaction rather than internal mechanisms.

Contribution

It provides the first detailed measurement of the bar pattern speed and dynamics in IC 3167, linking bar formation to external interactions in dwarf galaxies.

Findings

The bar in IC 3167 is likely slow-rotating with R ≈ 1.7.

The bar's slow rotation is more probable than fast rotation.

Interaction with the Virgo cluster likely triggered the bar formation.

Abstract

We present surface photometry and stellar kinematics of IC 3167, a dwarf galaxy hosting a lopsided weak bar and infalling into the Virgo cluster. We measured the bar radius and strength from broad-band imaging and bar pattern speed by applying the Tremaine-Weinberg method to stellar-absorption integral-field spectroscopy. We derived the ratio of the corotation radius to bar radius (R = 1.7 + 0.5 - 0.3) from stellar kinematics and bar pattern speed. The probability that the bar is rotating slowly is more than twice as likely as that the bar is fast. This allows us to infer that the formation of this bar was triggered by the ongoing interaction rather than to internal processes.