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Paper: Restframe I-band Hubble Diagram for Type Ia Supernovae up to Redshift z ∼ 0.5
Volume: 342, 1604-2004: Supernovae as Cosmological Lighthouses
Page: 253
Authors: Nobili, S.; Supernova Cosmology Project
Abstract: This poster uses a novel technique for fitting restframe I-band lightcurves of type Ia supernovae (SNIa), a Hubble diagram including 26 SNe with redshift 0.01 < z > 0.1 is constructed. Adding two SNe at z ∼ 0.5 yields results that support the expectation for a flat Λ dominated universe. The high redshift supernova NIR data was also used to test for systematic effects in the use of SNIa as distance estimators. A flat, Λ=0, universe where the faintness of supernovae at z ∼ 0.5 is due to gray dust homogeneously distributed in the intergalactic medium is disfavored based on the high-z Hubble diagram using this preliminary data set. However, the uncertainties are large and no firm conclusion may be drawn. It also shows that more supernovae are necessary to set limits on the intergalactic dust based on B—I and B—l;V color measurements. The high redshift restframe I-band lightcurves are better fit by templates that show a second peak than by templates without a second peak, suggesting that they are not intrinsically underluminous.
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