RemoveYoung: A tool for the removal of the young stellar component in
  galaxies within an adjustable age cutoff
  The optical morphology of galaxies holds the cumulative record of their
assembly history, and techniques for its quantitative characterization offer a
promising avenue toward understanding galaxy formation and evolution. However,
the morphology of star-forming galaxies is generally dictated by the youngest
stellar component, which can readily overshine faint structural/morphological
features in the older underlying stellar background (e.g., relics from recent
minor mergers) that could hold important insights into the galaxy build-up
process. Stripping off galaxy images from the emission from stellar populations
younger than an adjustable age cutoff tcut can, therefore, provide a valuable
tool in extragalactic research. RemoveYoung (RY), a publicly available tool
that is presented here, exploits the combined power of integral field
spectroscopy (IFS) and spectral population synthesis (SPS) toward this goal.
Two-dimensional (2D) post-processing of SPS models to IFS data cubes with RY
permits computation of the spectral energy, surface brightness, and stellar
surface density distribution of stellar populations older than a user-defined
tcut. This suggests a variety of applications of star-forming galaxies, such as
interacting or merging galaxy pairs and lower mass starburst galaxies near and
far; these include blue compact and tidal dwarf galaxies.
