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Abstract

This thesis is dedicated to answering one particular question: how relevant is pre-processing in shaping present-day properties of early-type dwarf galaxies (dEs) in massive clusters? With the intention of doing so, we present the analysis of the kinematics and stellar population properties of nine early-type dwarf galaxies (dEs) of the Virgo cluster. According to the results of Lisker et al. (2018), these nine dEs were accreted onto Virgo as gravitationally bound members of a massive galaxy group (M_{star} ∼ 10^13 M_{sun}) along the observer’s line of sight about 2-3 Gyr ago. We confirm a similar accretion time by investigating their distribution on the projected phase-space diagram. We performed full-spectrum fitting on the spatially binned MUSE/VLT data of these dEs to investigate their kinematics. We quantified their stellar rotation using specific angular momentum (λR) and derived diverse kinematic properties in our sample, despite their similar accretion time onto Virgo and stellar mass range. While half of our sample members show higher degrees of rotation, similar to low-mass star-forming field galaxies, the rest show kinematic profiles comparable with Virgo dEs with relatively larger average infall time. Furthermore, we employed Lick absorption features in each dEs’ MUSE data and performed a four-step fitting procedure (based on a χ2 minimization approach) to derive their stellar population properties. We detected relatively younger and metalpoorer stellar populations in these dEs that are noticeably α-enhanced than equally massive dEs in the Virgo and Coma clusters. Similar to other studies on cluster dEs, we detected flat age gradients, negative metallicity gradients, and positive [α/Fe] gradients for our sample dEs. By performing the full-spectrum fitting technique on their averaged MUSE spectra, we detected the presence of a significant peak in the star formation activity of some of our sample members, occurring at an epoch consistent with or even more recent than their accretion time onto Virgo. Through this thesis, we interpret our results by concurrently considering the role of pre-processing and early effects of the Virgo’s environment in shaping the observed properties of this unique Virgo dEs sample.