1022 articles – 5249 Notices  [english version]
 HAL : in2p3-00610569, version 1
 arXiv : 1103.2324
 Code Bibliographique ADS : 2011ApJ...733...3C
 Astrophysical Journal 733 (2011) 3
 Keck Observations of the Young Metal-Poor Host Galaxy of the Super-Chandrasekhar-Mass Type Ia Supernova SN 2007if
 (2011)
 We present Keck LRIS spectroscopy and $g$-band photometry of the metal-poor, low-luminosity host galaxy of the super-Chandrasekhar mass Type Ia supernova SN 2007if. Deep imaging of the host reveals its apparent magnitude to be $m_g=23.15\pm0.06$, which at the spectroscopically-measured redshift of $z_{helio}=0.07450\pm0.00015$ corresponds to an absolute magnitude of $M_g=-14.45\pm0.06$. Galaxy $g-r$ color constrains the mass-to-light ratio, giving a host stellar mass estimate of $\log(M_*/M_\odot)=7.32\pm0.17$. Balmer absorption in the stellar continuum, along with the strength of the 4000Å\ break, constrain the age of the dominant starburst in the galaxy to be $t_\mathrm{burst}=123^{+165}_{-77}$ Myr, corresponding to a main-sequence turn-off mass of $M/M_\odot=4.6^{+2.6}_{-1.4}$. Using the R$_{23}$ method of calculating metallicity from the fluxes of strong emission lines, we determine the host oxygen abundance to be $12+\log(O/H)_\mathrm{KK04}=8.01\pm0.09$, significantly lower than any previously reported spectroscopically-measured Type Ia supernova host galaxy metallicity. Our data show that SN 2007if is very likely to have originated from a young, metal-poor progenitor.
 Thème(s) : Physique/Astrophysique/Astrophysique galactiquePlanète et Univers/Astrophysique/Astrophysique galactique
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1103.2324
 in2p3-00610569, version 1 http://hal.in2p3.fr/in2p3-00610569 oai:hal.in2p3.fr:in2p3-00610569 Contributeur : Sylvie Florès <> Soumis le : Vendredi 22 Juillet 2011, 14:54:36 Dernière modification le : Vendredi 22 Juillet 2011, 15:02:13