Starburst-AGN mixing: II. Optically-selected active galaxies

Abstract

We use 4 galaxies from the Calar Alto Legacy Integral Field Area (CALIFA) survey with clear signs of accretion onto supermassive black holes to investigate the relative contribution of star-formation and active galactic nucleus (AGN) activity to the line-emission of each galaxy as a function of radius. The combination of star-formation and AGN activity produces curved "mixing sequences" on standard optical diagnostic diagrams, and the fraction of emission due to AGN activity decreases smoothly with distance from the centre of the galaxy. We use the AGN activity profiles to calculate the size of the AGN narrow line regions, which have radii of ~ 6.3 kpc. We calculate the fractional contribution of the star-formation and the AGN activity to the global Halpha, [O II] $\lambda \lambda$ 3727,3729 and [O III] $\lambda$ 5007 luminosities of each galaxy, and show that both ionization sources contribute significantly to the emission in all three lines. We use weighted combinations of stellar and AGN photoionization models to produce mixing models, which are consistent with observations for 85 percent of spaxels across the galaxies in our sample. We also present a new diagnostic for starburst-AGN mixing which requires only the [O II], [O III] and Hbeta emission lines, and can therefore be used to calculate AGN fractions up to z ~ 0.85 in the optical and z ~ 3.5 in the near-infrared. We anticipate that this diagnostic will facilitate studies of the properties of AGN ionizing radiation fields and the relative optical contribution of star-formation and AGN activity over cosmic time.

15 pages, 8 figures. Accepted for publication in MNRAS

References in corpus (15)

• The Host Galaxies and Classification of Active Galactic Nuclei
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• The Mass-Metallicity Relation at z~2
• The MAPPINGS III Library of Fast Radiative Shock Models
• A Close Look at Star Formation around Active Galactic Nuclei
• Rotational mixing in massive binaries: detached short-period systems
• CALIFA, the Calar Alto Legacy Integral Field Area survey. II. First public data release
• Resolving the electron temperature discrepancies in HII Regions and Planetary Nebulae: kappa-distributed electrons
• Simulations of Cosmic Chemical Enrichment
• Size and properties of the narrow-line region in Seyfert-1 galaxies from spatially-resolved optical spectroscopy
• AEGIS: New Evidence Linking Active Galactic Nuclei to the Quenching of Star Formation
• The role of AGN in the colour transformation of galaxies at redshifts z~1
• Intense Star-formation and Feedback at High Redshift: Spatially-resolved Properties of the z=2.6 Submillimeter Galaxy SMMJ14011+0252
• The Effects of Metallicity and AGN Activity on the Mid-Infrared Dust Emission of Galaxies
• Probing the physics of narrow-line regions of Seyfert galaxies I: The case of NGC 5427

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