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Date and Time of the Query: 2019-05-20 T01:14:28 PDT
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For refcode 2006ApJ...645..488W:
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Copyright by American Astronomical Society. Reproduced by permission
2006ApJ...645..488W Determination of the Hubble Constant, the Intrinsic Scatter of Luminosities of Type Ia Supernovae, and Evidence for Nonstandard Dust in Other Galaxies Xiaofeng Wang, Lifan Wang, Reynald Pain, Xu Zhou, and Zongwei Li Abstract. 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 {DELTA}C_12_ and the decline rate {DELTA}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 {DELTA}C_12_. The Hubble diagrams constructed using 73 Hubble flow SNe Ia yield a 1 {sigma} 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 {DELTA}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^. Key words: Stars: Variables: Cepheids, Cosmology: Cosmological Parameters, Cosmology: Observations, Cosmology: Distance Scale, ISM: Dust, Extinction, Stars: Supernovae: General
Retrieve 218 NED objects in this reference.
Please click here for ADS abstract

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