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标题：Precision of thermonuclear supernovae as distance indicators
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作者：I. Dominguéz ; E. Bravo ; L. Piersanti 等
期刊名称：PoS - Proceedings of Science
印刷版ISSN：1824-8039
出版年度：2007
卷号：2007
出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Observations of thermonuclear supernovae (SNe Ia) at high-redhift (z) show that the Universe is dominated by the Dark Energy term, characterized by its negative pressure. SNIa Hubble diagram, including nowadays 200 of these objects up to z=1.8, strongly favours a decelerated expansion of the Universe up to z=0.5 and an accelerated one at current time. Taken all current data together (SNe Ia, Cosmic Microwave Background, Barionic Acoustic Oscillations and Large Scale Structure) the fraction of the dark energy to the critical density is 70% and its EOS, w=P/r , is compatible with the cosmological constant or vacuum energy, w=-1, without a temporal dependence. However, any further attempt to characterize this EOS based on SNe Ia requires to reduce the present scatter in the Hubble diagram by a factor of 10. Ultimately, systematic effects, like extinction and evolution with z, and uncontrolled intrinsic dispersion of the light curve shapes will limit the precision by which SNe Ia could be used to probe the structure of the Universe and its time evolution. Moreover, observations indicate that brighter SNe Ia occur only in systems with ongoing star formation and that the majority of SNe Ia comes from young progenitors. In this work we focus on the scatter of the maximum luminosity of SNe Ia as determined by possible variation of some properties of their progenitors, namely: (a) mass and metallicity of the progenitor of the exploding white dwarf and (b) rotational velocity in the framework of double degenerate systems. We obtain differences up to 0.2 magnitudes at maximum, which are significant to explore the nature of the dark energy.