The Nature of galaxie � s LIN ER Robert Singh, Glenn v. d. Ven & Knud Jahnke
CALIFA • ~600 galaxies, diameter selected, 0.005<z<0.03 • Spatial sampling ~2” ≈ 0.5-1 kpc • Spectral resolution R~850 (v500)/ ~1650 (v1200) • Wavelength coverage 3400 – 7300 Å • 3 σ limiting surface brightness ~23.0 mag/arcsec 2 Robert Singh
LIN ER s L ow I onisation N uclear E mission-line R egion • • possible ionisation sources: � - low luminosity AGN - hot old stars (post-AGB) � - shocks (mergers, outflows) � • general properties: - old stellar pops - line emission from weakly ionised atoms - fraction with central X-ray - > 50% of the AGN population Robert Singh
[OIII] H α H α H α [NII] [OI] [SII] H β Robert Singh
85,224 SDSS galaxies Robert Singh
257 CALIFA galaxies Robert Singh
1 CALIFA galaxy NGC 2916 Robert Singh
BPT maps SF Seyfert Robert Singh
BPT maps NGC 5157 SF LINER Robert Singh
LI N ER emission Singh et al. 2013 10 1 normalised H alpha flux 10 0 10 -1 10 -2 10 -3 Singh et al. 2013 0 10 20 30 40 radius [arcsec] Robert Singh
UGC11680 SDSS Robert Singh
UGC11680 BPT map Robert Singh
UGC11680 Ha EW map EW Robert Singh
UGC11680 Ha EW map Histogram of LINER bins EW [Å] Robert Singh
EW(Ha) Robert Singh
star-formation histories Robert Singh
star-formation histories Seyfert like emission 6.76 Gyr Robert Singh
star-formation histories LINER like emission 4.47 Gyr Robert Singh
star-formation histories SF & intermediate emission 3.16 Gyr Robert Singh
star-formation histories light weighted log(age) Robert Singh
conclusion • Explanation of low-power AGN is not reconcilable with our results. • LINER signatures are not a good tool for finding AGN. � • LINERs can host an AGN. � • AGN activity does not explain non-nuclear LINER emission. • LINER emission does not imply an AGN origin • Ample evidence for hot old stars - spatial extend of LINER like emission - spatial correlation with low EW(Ha) - spatial correlation with older stellar ages Robert Singh
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