Ultraviolet Light Curves of Supernovae with Swift Uvot

TL;DR

This paper presents the largest collection of ultraviolet light curves of supernovae from Swift UVOT, revealing differences among types and aiding in supernova classification and analysis.

Contribution

It provides a comprehensive dataset of UV light curves across all major supernova types, enabling improved classification and bolometric analysis.

Findings

UV light curves are homogeneous for SNe Ia.

SNe Ib/c and IIP show diverse UV light curve shapes.

UV-optical colors differentiate supernova types, especially early on.

Abstract

We present ultravioliet (UV) observations of supernovae (SNe) obtained with the UltraViolet/Optical Telescope (UVOT) on board the Swift spacecraft. This is the largest sample of UV light curves from any single instrument and covers all major SN types and most subtypes. The UV light curves of SNe Ia are fairly homogenous while SNe Ib/c and IIP show more variety in their light curve shapes. The UV-optical colors clearly differentiate SNe Ia and IIP, particularly at early times. The color evolution of SNe IIP, however, makes their colors similar to SNe Ia at about 20 days after explosion. SNe Ib/c are shown to have varied UV-optical colors. The use of UV colors to help type SNe will be important for high redshift SNe discovered in optical observations. These data can be added to ground based optical and near infrared data to create bolometric light curves of individual objects and as checks on generic bolometric corrections used in the absence of UV data. This sample can also be compared with rest-frame UV observations of high redshift SNe observed at optical wavelengths.