SDSS-IV MaNGA: stellar population gradients as a function of galaxy
  environment
  We study the internal radial gradients of stellar population properties
within $1.5\;R_{\rm e}$ and analyse the impact of galaxy environment. We use a
representative sample of 721 galaxies with masses ranging between
$10^{9}\;M_{\odot}$ to $10^{11.5}\;M_{\odot}$ from the SDSS-IV survey MaNGA. We
split this sample by morphology into early-type and late-type galaxies. Using
the full spectral fitting code FIREFLY, we derive the light and mass-weighted
stellar population properties age and metallicity, and calculate the gradients
of these properties. We use three independent methods to quantify galaxy
environment, namely the $N^{th}$ nearest neighbour, the tidal strength
parameter $Q$ and distinguish between central and satellite galaxies. In our
analysis, we find that early-type galaxies generally exhibit shallow
light-weighted age gradients in agreement with the literature and mass-weighted
median age gradients tend to be slightly positive. Late-type galaxies, instead,
have negative light-weighted age gradients. We detect negative metallicity
gradients in both early and late-type galaxies that correlate with galaxy mass,
with the gradients being steeper and the correlation with mass being stronger
in late-types. We find, however, that stellar population gradients, for both
morphological classifications, have no significant correlation with galaxy
environment for all three characterisations of environment. Our results suggest
that galaxy mass is the main driver of stellar population gradients in both
early and late-type galaxies, and any environmental dependence, if present at
all, must be very subtle.
