Understanding the origin and evolution of dwarf early-type galaxies remains an important open issue in modern astrophysics .
Internal kinematics of a galaxy contains signatures of violent phenomena which may have occurred , e.g .
mergers or tidal interactions , while stellar population keeps a fossil record of the star formation history , therefore studying connection between them becomes crucial for understanding galaxy evolution .
Here , in the first paper of the series , we present the data on spatially resolved stellar populations and internal kinematics for a large sample of dwarf elliptical ( dE ) and lenticular ( dS0 ) galaxies in the Virgo cluster .
We obtained radial velocities , velocity dispersions , stellar ages and metallicities out to 1–2 half-light radii by re-analysing already published long-slit and integral-field spectroscopic datasets using the NBursts full spectral fitting technique .
Surprisingly , bright representatives of the dE/dS0 class ( M _ { B } = -18.0 \ldots - 16.0 mag ) look very similar to intermediate-mass and giant lenticulars and ellipticals : ( 1 ) their nuclear regions often harbour young metal-rich stellar populations always associated with the drops in the velocity dispersion profiles ; ( 2 ) metallicity gradients in the main discs/spheroids vary significantly from nearly flat profiles to -0.9 dex r _ { e } ^ { -1 } , i.e .
somewhat 3 times steeper than for typical bulges ; ( 3 ) kinematically decoupled cores were discovered in 4 galaxies , including two with very little , if any , large scale rotation .
These results suggest similarities in the evolutionary paths of dwarf and giant early-type galaxies and call for reconsidering the role of major mergers in the dE/dS0 evolution .