Age and Metallicity of galaxies in different environments of the Coma
  supercluster
  We analyse luminosity-weighted ages and metallicity (Z) of galaxies in a
continuous range of environments, i.e. clusters, filaments and voids prevalent
in the Coma supercluster ($\sim 100 h^{-1}$ Mpc). Specifically, we employ two
absorption line indices, H$\beta$ and $\langle\rm{Fe}\rangle$ as tracers of age
and metallicity of galaxies. We find that the stellar-phase metallicity of
galaxies declines with increasing age as a function of stellar mass ($M^*$) as
well as environment. On the filaments, metallicity of galaxies varies as a
function of their distance from the spine of the filament, such that galaxies
closer to the centre of the filaments have lower metallicity relative to their
counterparts 1 Mpc away from it. The mean age of intermediate mass galaxies
($10^{10} < M^*/M_{\odot} < 10^{10.5}$) galaxies is statistically significantly
different in different environments such that, the galaxies in clusters are
older than the filament galaxies by 1-1.5 Gyr, while their counterparts in the
voids are younger than filament galaxies by $\sim 1$ Gyr. The massive galaxies
($M^*/M_{\odot} > 10^{10.5}$), on the other hand show no such difference for
the galaxies in clusters and filaments, but their counterparts in voids are
found to be younger by $\sim 0.5$ Gyr. At fixed age however, Z of galaxies is
independent of their $M^*$ in all environments, except the most massive
($M^*/M_{\odot} \gtrsim 10^{10.7}$), oldest galaxies ($\gtrsim 9$ Gyr) which
show a sharp decline in their Z with $M^*$. Our results support a scenario
where galaxies in the nearby Universe have grown by accreting smaller galaxies
or primordial gas from the large-scale cosmic web.
