The first 62 AGN observed with SDSS-IV MaNGA - I: their characterization and definition of a control sample


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We report the characterization of the first $62$ MaNGA Active Galactic Nuclei (AGN) hosts in the Fifth Product Launch (MPL-5) and the definition of a control sample of non-active galaxies. This control sample - comprising two galaxies for each AGN - was selected in order to match the AGN hosts in terms of stellar mass, redshift, visual morphology and inclination. The stellar masses are in the range $9.4<log(M/M_odot)<11.5$, and most objects have redshifts $leq 0.08$. The AGN sample is mostly comprised of low-luminosity AGN, with only 17 nuclei with $L([OIII]lambda 5007)geq 3.8times 10^{40}$ erg s$^{-1}$ (that we call strong AGN). The stellar population of the control sample galaxies within the inner $1$-$3$ kpc is dominated by the old ($sim$ $4$ - $13$ Gyr) age component, with a small contribution of intermediate age ($sim 640$-$940$ Myr) and young stars ($leq 40$ Myr) to the total light at $5700AA$. While the weaker AGN show a similar age distribution to that of the control galaxies, the strong AGN show an increased contribution of younger stars and a decreased contribution of older stars. Examining the relationship between the AGN stellar population properties and $L([OIII])$, we find that with increasing $L([OIII])$, the AGN exhibit a decreasing contribution from the oldest ($>4$ Gyr) stellar population relative to control galaxies, but have an increasing contribution from the younger components with ages $sim 40$ Myr. We also find a correlation of the mean age differences (AGN - control) with $L([OIII])$, in the sense that more luminous AGN are younger than the control objects, while the low-luminosity AGN seem to be older. These results support a connection between the growth of the galaxy bulge via formation of new stars and the growth of the Supermassive Black Hole via matter accretion in the AGN phase.

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