# Near-Ultraviolet Properties of a Large Sample of Type Ia Supernovae as Observed with the Swift UVOT - Astrophysics > Cosmology and Nongalactic Astrophysics

Near-Ultraviolet Properties of a Large Sample of Type Ia Supernovae as Observed with the Swift UVOT - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We present ultraviolet UV and optical photometry of 26 Type Ia supernovaeSNe~Ia observed from March 2005 to March 2008 with the NASA {\it Swift}Ultraviolet and Optical Telescope UVOT. The dataset consists of 2133individual observations, making it by far the most complete study of the UVemission from SNe~Ia to date. Grouping the SNe into three subclasses as derivedfrom optical observations, we investigate the evolution of the colors of theseSNe, finding a high degree of homogeneity within the normal subclass, butdramatic differences between that group and the subluminous and SN 2002cx-likegroups. For the normal events, the redder UV filters on UVOT $u$, $uvw1$ showmore homogeneity than do the bluer UV filters $uvm2$, $uvw2$. Searching forpurely UV characteristics to determine existing optically based groupings, wefind the peak width to be a poor discriminant, but we do see a variation in thetime delay between peak emission and the late, flat phase of the light curves.The UV light curves peak a few days before the $B$ band for most subclasses aswas previously reported by Jha et al. 2006a, although the SN 2002cx-likeobjects peak at a very early epoch in the UV. That group also features thebluest emission observed among SNe~Ia. As the observational campaign isongoing, we discuss the critical times to observe, as determined by this study,in order to maximize the scientific output of future observations.

Autor: Peter A.Milne, Peter J. Brown, Peter W. A. Roming, Stephen T. Holland, Stefan Immler, Alexei V. Filippenko, Mohan Ganeshalingam,

Fuente: https://arxiv.org/