Simulations of collision and sloshing in the galaxy group NGC 5098/5096

TL;DR

This paper uses hydrodynamical simulations and X-ray data analysis to model the collision and gas sloshing in the galaxy groups NGC 5098 and 5096, revealing their dynamical interaction and distribution of dark matter and intragroup light.

Contribution

It presents a detailed simulation-based model of the galaxy group collision, matching observational X-ray data and constraining the collision geometry and dynamics.

Findings

Simulations reproduce observed X-ray surface brightness and gas sloshing.

Collision occurs nearly along the line of sight with an inclination of 80°.

Dark matter and intragroup light distributions are correlated.

Abstract

The study of galaxy groups is essential to understanding the evolutionary history of large-scale structures in the Universe. These dense environments have a significant impact on galaxy evolution, influencing their gas content, morphology, and star formation activity. In this work we analyse in detail the system NGC~5098$/$5096 composed of two galaxy groups. We performed hydrodynamical $N$-body simulations of a galaxy group collision aimed at reproducing the gas sloshing and surface brightness distribution observed in X-ray data. We conducted a detailed X-ray analysis and generated mock image \textit{Chandra} observations from our simulations. The resulting corrected mock image surface brightness profiles show good agreement with the observed data. The relative line-of-sight velocity between NGC~5098 and NGC~5096 is $v_{\mathrm{los}} = 700$ km s$^{-1}$, with a projected separation of $d_{\mathrm{proj}} = 155$ kpc, suggesting that the collision occurs nearly in the line-of-sight. Our simulations were performed with an inclination angle of $80^\circ$ in order to reproduce the dynamical constraints. We also find a correlation between the dark matter and intragroup light distributions when comparing the residual dark matter map with the intragroup light morphology. Our best-fitting model is consistent with these observational constraints and provides a plausible dynamical scenario for the current state of the NGC~5098 group interaction with NGC 5096.