Shell Galaxies: Dynamical Friction, Gradual Satellite Decay and Merger Dating

TL;DR

This paper introduces a new simulation method for shell galaxies that incorporates dynamical friction and gradual satellite decay, improving the accuracy of merger history analysis.

Contribution

It develops a novel approach combining dynamical friction and satellite decay in test-particle simulations for better shell galaxy modeling.

Findings

Coupling dynamical friction with satellite decay significantly alters shell positions and luminosities.

Neglecting these effects can cause substantial errors in merger dating.

The method enhances the precision of using shells to probe galaxy merger histories.

Abstract

With the goal to refine modelling of shell galaxies and the use of shells to probe the merger history, we develop a new method for implementing dynamical friction in test-particle simulations of radial minor mergers. The friction is combined with a gradual decay of the dwarf galaxy. The coupling of both effects can considerably redistribute positions and luminosities of shells; neglecting them can lead to significant errors in attempts to date the merger.