Star-forming Dwarf Galaxies in Filamentary Structures around the Virgo
  Cluster: Probing Chemical Pre-processing in Filament Environments
  It has been proposed that the filament environment is closely connected to
the pre-processing of galaxies, where their properties may have been changed by
environmental effects in the filament before they fell into the galaxy cluster.
We present the chemical properties of star-forming dwarf galaxies (SFDGs) in
five filamentary structures (Virgo III, Leo Minor, Leo II A, Leo II B, and
Canes Venatici) around the Virgo cluster using the Sloan Digital Sky Survey
optical spectroscopic data and Galaxy Evolution Explorer ultraviolet
photometric data. We investigate the relationship between stellar mass,
gas-phase metallicity, and specific star formation rate (sSFR) of SFDGs in the
Virgo filaments in comparison to those in the Virgo cluster and field. We find
that, at a given stellar mass, SFDGs in the Virgo filaments show lower
metallicity and higher sSFR than those in the Virgo cluster on average. We
observe that SFDGs in the Virgo III filament show enhanced metallicities and
suppressed star formation activities comparable to those in the Virgo cluster,
whereas SFDGs in the other four filaments exhibit similar properties to the
field counterparts. Moreover, about half of the galaxies in the Virgo III
filament are found to be morphologically transitional dwarf galaxies that are
supposed to be on the way to transforming into quiescent dwarf early-type
galaxies. Based on the analysis of the galaxy perturbation parameter, we
propose that the local environment represented by the galaxy interactions might
be responsible for the contrasting features in "chemical pre-processing" found
in the Virgo filaments.
