The Bridge Effect of Void Filaments
  Cosmic filaments play a role of bridges along which matter and gas accrete
onto galaxies to trigger star formation and feed central black holes. Here we
explore the correlations between the intrinsic properties of void galaxies and
the linearity R_L of void filaments (degree of filament's straightness). We
focus on void regions since the bridge effect of filaments should be most
conspicuous in the pristine underdense regions like voids. Analyzing the
Millennium-Run semi-analytic galaxy catalogue, we identify void filaments
consisting of more than four galaxies (three edges) and calculate the means of
central black hole mass, star formation rate, and stellar mass as a function of
R_L. It is shown that the void galaxies constituting more straight filaments
tend to have higher luminosity, more massive central black holes and higher
star formation rate. Among the three properties, the central black hole mass is
most strongly correlated with R_L. It is also shown that the dark halos
constituting straight filaments tend to have similar masses. Our results
suggest that the fuel-supply for central black holes and star formation of void
galaxies occurs most efficiently along straight void filaments whose potential
wells are generated by similar-mass dark halos.
