2011/03/11 by M. Childress, G. Aldering, C. Aragon +31 · 2 citations
Physics and Astronomy · #Absolute magnitude #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Chandrasekhar limit #Galaxy #Gamma-ray bursts and supernovae #Metallicity #Photometry (optics) #Physics #Star formation #Stars #Stellar mass #Supernova #White dwarf #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/733/1/3
15 pages, 9 figures; accepted for publication in ApJ
arxiv created 2011/03/11 · openalex publication_date 2011/04/27 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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 ± 0.06, which at the spectroscopically measured redshift of z helio = 0.07450 ± 0.00015 corresponds to an absolute magnitude of M g = −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 Å 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.