Mon. Not. R. Astron. Soc., 449, 867-900 (2015/May-1)
P-MaNGA Galaxies: emission-lines properties - gas ionization and chemical abundances from prototype observations.
BELFIORE F., MAIOLINO R., BUNDY K., THOMAS D., MARASTON C., WILKINSON D., SANCHEZ S.F., BERSHADY M., BLANC G.A., BOTHWELL M., CALES S.L., COCCATO L., DRORY N., EMSELLEM E., FU H., GELFAND J., LAW D., MASTERS K., PAREJKO J., TREMONTI C., WAKE D., WEIJMANS A., YAN R., XIAO T., ZHANG K., ZHENG T., BIZYAEV D., KINEMUCHI K., ORAVETZ D. and SIMMONS A.
Abstract (from CDS):
MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-yr Sloan Digital Sky Survey (SDSS-IV) survey that will obtain spatially resolved spectroscopy from 3600 to 10 300Å for a representative sample of over 10 000 nearby galaxies. In this paper, we present the analysis of nebular emission-line properties using observations of 14 galaxies obtained with P-MaNGA, a prototype of the MaNGA instrument. By using spatially resolved diagnostic diagrams, we find extended star formation in galaxies that are centrally dominated by Seyfert/LINER-like emission, which illustrates that galaxy characterizations based on single fibre spectra are necessarily incomplete. We observe extended low ionization nuclear emission-line regions (LINER)-like emission (up to 1Re) in the central regions of three galaxies. We make use of the Hα equivalent width [EW(Hα)] to argue that the observed emission is consistent with ionization from hot evolved stars. We derive stellar population indices and demonstrate a clear correlation between Dn(4000) and EW(HδA) and the position in the ionization diagnostic diagram: resolved galactic regions which are ionized by a Seyfert/LINER-like radiation field are also devoid of recent star formation and host older and/or more metal-rich stellar populations. We also detect extraplanar LINER-like emission in two highly inclined galaxies, and identify it with diffuse ionized gas. We investigate spatially resolved metallicities and find a positive correlation between metallicity and star formation rate surface density. We further study the relation between N/O versus O/H on resolved scales. We find that, at given N/O, regions within individual galaxies are spread towards lower metallicities, deviating from the sequence defined by galactic central regions as traced by Sloan 3-arcsec fibre spectra. We suggest that the observed dispersion can be a tracer for gas flows in galaxies: infalls of pristine gas and/or the effect of a galactic fountain.
© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2015)
galaxies: abundances - galaxies: active - galaxies: evolution - galaxies: fundamental parameters - galaxies: ISM
View the references in ADS
To bookmark this query, right click on this link: simbad:2015MNRAS.449..867B and select 'bookmark this link' or equivalent in the popup menu