Measurement of Ωm, ΩΛfrom a Blind Analysis of Type Ia Supernovae with CMAGIC: Using Color Information to Verify the Acceleration of the Universe
| Autor: | N. Kuznetsova, S. Nobili, A. L. Spadafora, D. A. Howell, R. A. Knop, M. Kowalski, Greg Aldering, G. Garavini, I. M. Hook, Lingyu Wang, Eric P. Smith, R. Pain, Saul Perlmutter, G. Goldhaber, W. M. Wood-Vasey, Vallery Stanishev, M. Strovink, R. C. Thomas, A. G. Kim, Rahman Amanullah, A. Goobar, D. E. Groom, G. Folatelli, Eugene D. Commins, C. Lidman, R. Gibbons, Peter Nugent, Alex Conley, Vitaliy Fadeyev |
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| Rok vydání: | 2006 |
| Předmět: |
Physics
010308 nuclear & particles physics Shape of the universe Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Cosmological constant Astrophysics Type (model theory) Lambda 01 natural sciences Omega Galaxy Cosmology Supernova Space and Planetary Science 0103 physical sciences 010303 astronomy & astrophysics |
| Zdroj: | The Astrophysical Journal. 644:1-20 |
| ISSN: | 1538-4357 0004-637X |
| Popis: | We present measurements of \Omega_m and \Omega_{\Lambda} from a blind analysis of 21 high-redshift supernovae using a new technique (CMAGIC) for fitting the multi-color lightcurves of Type Ia supernovae, first introduced in Wang et al. (2003). CMAGIC takes advantage of the remarkably simple behavior of Type Ia supernovae on color-magnitude diagrams, and has several advantages over current techniques based on maximum magnitudes. Among these are a reduced sensitivity to host galaxy dust extinction, a shallower luminosity-width relation, and the relative simplicity of the fitting procedure. This allows us to provide a cross check of previous supernova cosmology results, despite the fact that current data sets were not observed in a manner optimized for CMAGIC. We describe the details of our novel blindness procedure, which is designed to prevent experimenter bias. The data are broadly consistent with the picture of an accelerating Universe, and agree with a flat Universe within 1.7\sigma, including systematics. We also compare the CMAGIC results directly with those of a maximum magnitude fit to the same SNe, finding that CMAGIC favors more acceleration at the 1.6\sigma level, including systematics and the correlation between the two measurements. A fit for w assuming a flat Universe yields a value which is consistent with a cosmological constant within 1.2\sigma. |
| Databáze: | OpenAIRE |
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