%0 Journal Article
%A Marino, Raffaella Anna
%T Nearby supernova host galaxies from the CALIFA survey II. Supernova environmental metallicity
%D 2016
%@ 1432-0746
%U https://hdl.handle.net/20.500.14352/23857
%X The metallicity of a supernova progenitor, together with its mass, is one of the main parameters that can rule their outcome. We present the second study of nearby supernova (SN) host galaxies (0.005 < z < 0.03) using Integral Field Spectroscopy (IFS) from the CALIFA survey. We analyze the metallicity of 115 galaxies, which hosted 132 SNe within and 10 SNe outside the field-of-view (FoV) of the instrument. Further 18 galaxies, which hosted only SNe outside the FoV were also studied. Using the O3N2 calibrator from Marino et al. (2013) we found no statistically significant differences between the gas-phase metallicities at the locations of the three main SN types – Ia, Ib/c and II, all having 12 + log(O/H) ≃ 8.50 within 0.02 dex. The total galaxy metallicities are also very similar and we argue that this is because our sample consists only of SNe discovered in massive galaxies (log(M/Mꙩ) > 10 dex) by targeted searches. We also found no evidence that the metallicity at the SN location differs from the average metallicity at the galactocentric distance of the SNe. By extending our SN sample with published metallicities at the SN location, we are able to study the metallicity distributions for all SN subtypes split into SN discovered in targeted and untargeted searches. We confirm a bias toward higher host masses and metallicities in the targeted searches. Combining data from targeted and untargeted searches we found a sequence from higher to lower local metallicity: SN Ia, Ic, and II show the highest metallicity, which is significantly higher than SN Ib, IIb, and Ic-BL. Our results support the picture of SN Ib resulting from binary progenitors and, at least part of, SN Ic being the result of single massive stars stripped of their outer layers by metallicity driven winds. We studied several proxies of the local metallicity frequently used in the literature and found that the total host metallicity allows for the estimation of the metallicity at the SN location with an accuracy better than 0.08 dex and very small bias. In addition, weak AGNs that cannot be seen in the total spectrum may weakly bias (by 0.04 dex) the metallicity estimate from the galaxy integrated spectrum.
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