The Fornax3D project: The assembly history of massive early-type galaxies in the Fornax cluster from deep imaging and integral field spectroscopy

TL;DR

This study uses deep imaging and integral-field spectroscopy to analyze the structural, kinematic, and stellar population properties of early-type galaxies in the Fornax cluster, revealing insights into their assembly history and environmental effects.

Contribution

It provides new observational evidence on the assembly processes of massive early-type galaxies in the Fornax cluster using combined deep imaging and integral-field spectroscopy data.

Findings

Galaxies in the cluster core show milder metallicity gradients.

Infalling galaxies exhibit different age and metallicity profiles.

Environmental segregation influences galaxy properties in Fornax.

Abstract

This work is based on high quality integral-field spectroscopic data obtained with the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT). The 21 brightest ($m_B\leq 15$ mag) early-type galaxies (ETGs) inside the virial radius of the Fornax cluster are observed out to distances of $\sim2-3\ R_{\rm e}$. Deep imaging from the VLT Survey Telescope (VST) is also available for the sample ETGs. We investigate the variation of the galaxy structural properties as a function of the total stellar mass and cluster environment. Moreover, we correlate the size scales of the luminous components derived from a multi-component decomposition of the VST surface-brightness radial profiles of the sample ETGs with the MUSE radial profiles of stellar kinematic and population properties. The results are compared with both theoretical predictions and previous observational studies and used to address the assembly history of the massive ETGs of the Fornax cluster. We find that galaxies in the core and north-south clump of the cluster, which have the highest accreted mass fraction, show milder metallicity gradients in their outskirts than the galaxies infalling into the cluster. We also find a segregation in both age and metallicity between the galaxies belonging to the core and north-south clump and the infalling galaxies. The new findings fit well within the general framework for the assembly history of the Fornax cluster.