Detection of a Type IIn Supernova in Optical Follow-up Observations of IceCube Neutrino Events

Understand

The IceCube neutrino observatory pursues a follow-up program selecting interesting neutrino events in real-time and issuing alerts for electromagnetic follow-up observations.

• In March 2012, the most significant neutrino alert during the first three years of operation was issued by IceCube.
• In the follow-up observations performed by the Palomar Transient Factory (PTF), a Type IIn supernova (SN) PTF12csy was found $0.2^\circ$ away from the neutrino alert direction, with an error radius of $0.54^\circ$.
• It has a redshift of $z=0.0684$, corresponding to a luminosity distance of about $300 \, \mathrm{Mpc}$ and the Pan-STARRS1 survey shows that its explosion time was at least 158 days (in host galaxy rest frame) before the neutrino alert, so that a causal connection is unlikely.