2006/03/23 by Xiaofeng Wang, Lifan Wang, R. Pain +3 · 3 citations
Physics and Astronomy · #Absolute magnitude #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Cosmic distance ladder #Extinction (optical mineralogy) #Galaxy #Gamma-ray bursts and supernovae #Hubble's law #Light curve #Luminosity #Metallicity #Milky Way #Physics #Redshift #Stellar, planetary, and galactic studies #Supernova #astro-ph
paper · pdf · doi:10.1086/504312
published as Astrophys.J.645:488-505,2006 · 40 pages, 9 figures, ApJ in press
arxiv created 2006/03/23 · openalex publication_date 2006/07/01 · arxiv updated 2010/04/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A sample of 109 Type Ia supernovae (SNe Ia) with recession velocity ≲30,000 km s -1 is compiled from published SN Ia light curves to explore the expansion rate of the local universe. Based on the color parameter Δ C 12 and the decline rate Δ m 15 , we found that the average absorption-to-reddening ratios for SN Ia host galaxies are R UBVI = 4.37 ± 0.25, 3.33 ± 0.11, 2.30 ± 0.11, and 1.18 ± 0.11, which are systematically lower than the standard values in the Galaxy. We investigated the correlations of the intrinsic luminosity with light-curve decline rate, color index, and SN environmental parameters. In particular, we found that SNe Ia in E/S0 galaxies close to the central region are brighter than those in the outer region, which may suggest a possible metallicity effect on SN luminosity. The dependence of SN luminosity on galactic environment disappears after corrections for the extinction and Δ C 12 . The Hubble diagrams constructed using 73 Hubble flow SNe Ia yield a 1 σ scatter of ≲0.12 mag in BVI bands and ~0.16 mag in U band. The luminosity difference between normal SNe Ia and peculiar objects (including SN 1991bg-like and SN 1991T-like events) has now been reduced to within 0.15 mag via Δ C 12 correction. We use the same precepts to correct the nearby SNe Ia with Cepheid distances and found that the fully corrected absolute magnitudes of SNe Ia are M B = -19.33 ± 0.06 and M V = -19.27 ± 0.05. We deduced a value for the Hubble constant of H 0 = 72 ± 6 (total) km s -1 Mpc -1 .