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arXiv · 1211.1362

Fixing the U-band photometry of Type Ia supernovae

Kevin Krisciunas·Deepak Bastola·Juan Espinoza·David Gonzalez·Luis Gonzalez·Sergio Gonzalez·Mario Hamuy·Eric Y. Hsiao·Nidia Morrell·Mark M. Phillips·Nicholas B. Suntzeff
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Abstract

We present previously unpublished photometry of supernovae 2003gs and 2003hv. Using spectroscopically-derived corrections to the U-band photometry, we reconcile U-band light curves made from imagery with the Cerro Tololo 0.9-m, 1.3-m and Las Campanas 1-m telescopes. Previously, such light curves showed a 0.4 mag spread at one month after maximum light. This gives us hope that a set of corrected ultraviolet light curves of nearby objects can contribute to the full utilization of rest frame U-band data of supernovae at redshift ~0.3 to 0.8. As pointed out recently by Kessler et al. in the context of the Sloan Digital Sky Survey supernova search, if we take the published U-band photometry of nearby Type Ia supernovae at face value, there is a 0.12 mag U-band anomaly in the distance moduli of higher redshift objects. This anomaly led the Sloan survey to eliminate from their analyses all photometry obtained in the rest frame U-band. The Supernova Legacy Survey eliminated observer frame U-band photometry, which is to say nearby objects observed in the U-band, but they used photometry of high redshift objects no matter in which band the photons were emitted.

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Kevin Krisciunas, Deepak Bastola, Juan Espinoza, David Gonzalez, Luis Gonzalez, Sergio Gonzalez, Mario Hamuy, Eric Y. Hsiao, Nidia Morrell, Mark M. Phillips, Nicholas B. Suntzeff. 2012-11-06. Fixing the U-band photometry of Type Ia supernovae. https://doi.org/10.1088/0004-6256%2F145%2F1%2F11

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