Akademska digitalna zbirka SLovenije - logo
E-viri
Recenzirano Odprti dostop
  • Keck Observations of the Yo...
    Childress, M; Aldering, G; Aragon, C; Antilogus, P; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Chotard, N; Copin, Y; Fakhouri, H. K; Gangler, E; Kerschhaggl, M; Kowalski, M; Hsiao, E. Y; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Runge, K; Scalzo, R; Thomas, R. C; Smadja, G; Tao, C; Weaver, B. A; Wu, C

    The Astrophysical journal, 05/2011, Letnik: 733, Številka: 1
    Journal Article

    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 mg = 23.15 ? 0.06, which at the spectroscopically measured redshift of z helio = 0.07450 ? 0.00015 corresponds to an absolute magnitude of Mg = --14.45 ? 0.06. Galaxy g -- r color constrains the mass-to-light ratio, giving a host stellar mass estimate of log(M */M ) = 7.32 ? 0.17. Balmer absorption in the stellar continuum, along with the strength of the 4000 A break, constrains the age of the dominant starburst in the galaxy to be t burst = 123+165 --77 Myr, corresponding to a main-sequence turnoff mass of M/M = 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)KK04 = 8.01 ? 0.09, 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.