Optical follow-up of high-energy neutrinos detected by IceCube

TL;DR

This paper describes an optical follow-up system for high-energy neutrinos detected by IceCube, aiming to identify transient astrophysical sources like supernovae and gamma-ray bursts through coordinated optical and neutrino observations.

Contribution

It introduces a novel real-time follow-up program combining neutrino detection with optical observations to enhance transient source identification.

Findings

First sensitivity assessment of the optical follow-up system.

Implementation of automated alerts for neutrino multiplets.

Integration with gamma-ray satellite data for coincidence analysis.

Abstract

Three-quarters of the 1 cubic kilometer neutrino telescope IceCube is currently taking data. Current models predict high-energy neutrino emission from transient objects like supernovae (SNe) and gammaray bursts (GRBs). To increase the sensitivity to such transient objects we have set up an optical follow-up program that triggers optical observations on multiplets of high-energy muon-neutrinos. We define multiplets as a minimum of two muon-neutrinos from the same direction (within 4 deg) that arrive within a 100 s time window. When this happens, an alert is issued to the four ROTSE-III telescopes, which immediately observe the corresponding region in the sky. Image subtraction is applied to the optical data to find transient objects. In addition, neutrino multiplets are investigated online for temporal and directional coincidence with gamma-ray satellite observations issued over the Gamma-Ray Burst Coordinate Network. An overview of the full program is given, from the online selection of neutrino events to the automated follow-up, and the resulting sensitivity to transient neutrino sources is presented for the first time.