The Herschel Virgo Cluster Survey. XIX. Physical properties of low
  luminosity FIR sources at $z <$ 0.5
  The Star formation rate (SFR) is a crucial parameter to investigate galaxy
evolution. At low redshift the cosmic SFR density declines smoothly, and
massive active galaxies become passive, reducing their star formation activity.
This implies that the bulk of the SFR density at low redshift is mainly driven
by low mass objects. We investigate the properties of a sample of low
luminosity Far-Infrared (FIR) sources selected at 250 microns from Pappalardo
et al. (2015). We have collected data from Ultraviolet to FIR to perform a
multi-wavelengths analysis. The main goal is to investigate the correlation
between SFR, stellar mass, and dust mass for a galaxy population with a wide
range in dust content and stellar mass, including the low mass regime that most
probably dominates the SFR density at low z. We define a main sample of ~800
sources with full Spectral Energy Distribution (SED) coverage between 0.15 <
lambda < 500 microns and an extended sample with ~5000 sources in which we
remove the constraints on the Ultraviolet and Near-Infrared bands. We analyze
both samples with two different SED fitting methods: MAGPHYS and CIGALE. In the
SFR versus stellar mass plane our samples occupy a region included between
local spirals and higher redshift star forming galaxies. The galaxies subsample
with the higher masses (M* > 3e10 Msol) does not lie on the main sequence, but
shows a small offset, as a consequence of the decreased star formation. Low
mass galaxies (M* < 1e10 Msol) settle in the main sequence with SFR and stellar
mass consistent with local spirals. Deep Herschel data allow the identification
of a mixed galaxy population, with galaxies still in an assembly phase, or
galaxies at the beginning of their passive evolution. We find that the dust
luminosity is the parameter that discriminates these two galaxy populations.
