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arXiv · 1201.1279

Studying Supernovae in the Near-Ultraviolet with the NASA Swift UVOT Instrument

P. A. Milne·P. J. Brown
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Abstract

Observations in the near- and mid-ultraviolet (NUV: 2000--3500$Å$) performed with the NASA Swift UVOT instrument have revealed that optically-normal SNe Ia feature NUV-optical color evolution that can be divided into NUV-blue and NUV-red groups, with roughly one-third of the observed events exhibiting NUV-blue color curves. Combined with an apparent correlation between NUV-blue events and the detection of unburned carbon in the optical spectra, the grouping might point to a fundamental difference within the normal SN Ia classfication. Recognizing the dramatic temporal evolution of the NUV-optical colors for all SNe Ia, as well as the existence of this sub-division, is important for studies that compare nearby SNe Ia with intermediate or high-$z$ events, for the purpose of the cosmological utilization of SNe Ia. SN 2011fe is shown to be of the NUV-blue groups, which will be useful towards interpretation of the gamma-ray line results from the INTEGRAL SPI campaign on SN 2011fe.

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P. A. Milne, P. J. Brown. 2012-01-05. Studying Supernovae in the Near-Ultraviolet with the NASA Swift UVOT Instrument. https://arxiv.org/abs/1201.1279

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