We present spaxel-by-spaxel stellar population fits for the ∼10 thousand
MaNGA datacubes. We provide multiple extension fits files, nominated as
MEGACUBES, with maps of several properties as well as emission-line profiles
that are provided for each spaxel. All the MEGACUBES are available through a
web interface (https://manga.linea.org.br/ or
http://www.if.ufrgs.br/~riffel/software/megacubes/). We also defined a final
Active Galactic Nuclei (AGN) sample, as well as a control sample matching the
AGN host galaxy properties. We have analysed the stellar populations and
spatially resolved emission-line diagnostic diagrams of these AGNs and compared
them with the control galaxies sample. We find that the relative fractions of
young (t≤56 Myr) and intermediate-age (100 Myr ≤t≤ 2 Gyr) show
predominantly a positive gradient for both AGNs and controls. The relative
fraction of intermediate-age stellar population is higher in AGN hosts when
compared to the control sample, and this difference becomes larger for higher
[O III] luminosity AGNs. We attribute this to the fact that extra gas is
available in these more luminous sources and that it most likely originates
from mass-loss from the intermediate-age stars. The spatially resolved
diagnostic diagrams reveal that the AGN emission is concentrated in the inner
0.5 Re (effective radius) region of the galaxies, showing that the AGN
classification is aperture dependent and that emission-line ratios have to be
taken together with the Hα equivalent width for proper activity
classification. We present a composite "BPT+WHAN" diagram that produces a more
comprehensive mapping of the gas excitation.Comment: Accepted for publication in MNRA