First all-flavor search for transient neutrino emission using 3-years of IceCube DeepCore data

TL;DR

This paper presents the first all-flavor search for transient low-energy neutrino emission using three years of IceCube-DeepCore data, focusing on the 5.6-100 GeV energy range, and finds no evidence of such emission.

Contribution

It introduces a novel all-flavor, sub-TeV transient neutrino search method using IceCube-DeepCore data, expanding the energy range of previous searches.

Findings

No evidence of transient neutrino emission was found.

Constraints on the rate of astrophysical transient sources were established.

The search covers the 5.6-100 GeV energy range over three years.

Abstract

Since the discovery of a flux of high-energy astrophysical neutrinos, searches for their origins have focused primarily at TeV-PeV energies. Compared to sub-TeV searches, high-energy searches benefit from an increase in the neutrino cross section, improved angular resolution on the neutrino direction, and a reduced background from atmospheric neutrinos and muons. However, the focus on high energy does not preclude the existence of sub-TeV neutrino emission where IceCube retains sensitivity. Here we present the first all-flavor search from IceCube for transient emission of low-energy neutrinos, focusing on the energy region of 5.6-100 GeV using three years of data obtained with the IceCube-DeepCore detector. We find no evidence of transient neutrino emission in the data, thus leading to a constraint on the volumetric rate of astrophysical transient sources in the range of $\sim 705-2301\, \text{Gpc}^{-3}\, \text{yr}^{-1}$ for sources following a subphotospheric energy spectrum with a mean energy of 100 GeV and a bolometric energy of $10^{52}$ erg.