Figure 1: The UBVR template light curves obtained after the training phase for different values of the stretch and null color. Note the strong variations of the U-band maximum with the stretch. Note also the after max shoulders in the V and R bands. The model also reproduces well the fact that the brighter-slower relation is weaker in the R band than in the B or V bands. The model does not incorporate the brighter-slower correlation. The apparent brighter-slower correlation for the U band is, in fact, a stretch-color correlation. | |
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Figure 2: Residuals to the light curve fit as a function of phase, for supernovae from the training sample (open symbols) and the test sample (filled symbols). There is no significant difference between the distributions obtained with both samples which proves that the model is not over-trained. The systematic residuals as a function of phase are a direct consequence of the limited number of parameters (5) used to implement the corrections as a function of phase. Increasing this number would remove this systematic trend in residuals, but some parameters would be poorly constrained in the U band where photometric data is scarce. | |
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Figure 3: The color correction as a function of wavelength for a value of c of 0.1 (thick line). The shaded area corresponds to one standard deviation to the best fit value. The dashed curve represents the extinction with respect to B band, , from Cardelli et al. (1989) with R_{V}=3.1 and E(B-V)=0.1. The curves are compatible in the R band but not in the U band (by construction they match in B and V bands as illustrated with the open circles). | |
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Figure 4: From top to bottom: residuals to the Hubble diagram as a function of redshift, stretch s and color c indexes for supernovae of the test sample fitted in B and V bands. SNe with redshifts smaller than 0.015 are labeled with opened symbols. | |
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Figure 5: 68% joint confidence regions for fitted using either UB or BV light curves of the test sample. The crosses show the best fitted values with uncertainties. | |
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Figure 6: From top to bottom: residuals to the Hubble diagram as a function of redshift, stretch s and color c indexes for supernovae of the test sample fitted in U and B bands. The values of used here are those fitted using B and V bands as described in the text. SNe with redshifts smaller than 0.015 are labeled with opened symbols. Note the large uncertainty affecting one SN (1996bo) due to its limited U-band photometry, and which also appears as a 2 sigma outlier in the 3 plots. | |
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Figure 7: Differences of s and c values fitted with either UB or BV light curves of supernovae from the training and the test sample (respectively opened and filled symbols). The error bars only reflect the propagation of photometric errors and do not account for any intrinsicdispersion. | |
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