Nearby supernova host galaxies from the CALIFA survey

II. Supernova environmental metallicity

¹ Millennium Institute of Astrophysics, Santiago, Chile
e-mail: lgalbany@das.uchile.cl
² Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
³ CENTRA – Centro Multidisciplinar de Astrofísica and Departamento de Física, Instituto Superior Técnico, ULisboa, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
⁴ European Southern Observatory, Alonso de Cordova 3107 Casilla 19001 –, Vitacura – Santiago, Chile
⁵ GEPI, Observatoire de Paris, UMR 8111, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92190 Meudon, France
⁶ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
⁷ Instituto de Astronomía, Universidad Nacional Autónoma de México, A.P. 70-264, 04510 México, D.F., Mexico
⁸ Instituto de Astrofśica de Andalucía (CSIC), Glorieta de la Astronomía s/n, Aptdo. 3004, 18080 Granada, Spain
⁹ Instituto de Cosmologia, Relatividade e Astrofísica – ICRA, Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, CEP, 22290-180 Rio de Janeiro, RJ, Brazil
¹⁰ Department of Physics and Astronomy, University of Pittsburgh, Allen Hall, 3941 O’Hara St, Pittsburgh PA 15260, USA
¹¹ Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands
¹² Department of Physics, Institute for Astronomy, ETH Zürich, 8093 Zürich, Switzerland
¹³ Departamento de Astrofísica y CC. de la Atmósfera, Facultad de CC. Físicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain
¹⁴ Departamento de Investigación Básica, CIEMAT, Avda. Complutense 40, 28040 Madrid, Spain
¹⁵ Max-Planck-Institut für Astronomie/Königstuhl 17, 69117 Heidelberg, Germany

Received: 25 December 2015
Accepted: 15 April 2016

Abstract

The metallicity of a supernova progenitor, together with its mass, is one of the main parameters that can rule the progenitor’s fate. 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. Another 18 galaxies, which hosted only SNe outside the FoV, were also studied. Using the O3N2 calibrator that was described elsewhere, 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; they all have 12 + log (O/H) ≃ 8.50 within 0.02 dex. The total galaxy metallicities are also very similar, and we argue that the reason is that our sample only consists of SNe discovered in massive galaxies (log (M/M_⊙) > 10 dex) by targeted searches. We neither found 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. By 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 those of SN Ib, IIb, and Ic-BL. Our results support the scenario according to which SN Ib result from binary progenitors. Additionally, at least part of the SN Ic are the result of single massive stars that were stripped of their outer layers by metallicity-driven winds. We studied several proxies of the local metallicity that are frequently used in the literature and found that the total host metallicity allows estimating 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 that is derived from the galaxy-integrated spectrum.