SNEWS 2.0: a next-generation supernova early warning system for multi-messenger astronomy

Abstract

The next core-collapse supernova in the Milky Way or its satellites will represent a once-in-a-generation opportunity to obtain detailed information about the explosion of a star and provide significant scientific insight for a variety of fields because of the extreme conditions found within. Supernovae in our galaxy are not only rare on a human timescale but also happen at unscheduled times, so it is crucial to be ready and use all available instruments to capture all possible information from the event. The first indication of a potential stellar explosion will be the arrival of a bright burst of neutrinos. Its observation by multiple detectors worldwide can provide an early warning for the subsequent electromagnetic fireworks, as well as signal to other detectors with significant backgrounds so they can store their recent data. The supernova early warning system (SNEWS) has been operating as a simple coincidence between neutrino experiments in automated mode since 2005. In the current era of multi-messenger astronomy there are new opportunities for SNEWS to optimize sensitivity to science from the next galactic supernova beyond the simple early alert. This document is the product of a workshop in June 2019 towards design of SNEWS 2.0, an upgraded SNEWS with enhanced capabilities exploiting the unique advantages of prompt neutrino detection to maximize the science gained from such a valuable event.

An End-to-End Test of the Sensitivity of IceCube to the Neutrino Burst from a Core-Collapse Supernova

“…• How does external information, such as detection of pre-supernova neutrinos by another experiment [8], affect our handling of low significance alerts?…”

“…IceCube is a key component of the SuperNova Early Warning System (SNEWS 2.0) [8], a network of neutrino detectors designed to give advanced notice of imminent photons from a nearby CCSN. By identifying coincidences between the arrival times of neutrino bursts in detectors around the world, SNEWS is intended to facilitate robust optical follow-ups of CCSNe.…”

KM3NeT Core Collapse Supernovae observation program in standalone and multi-messenger modes

“…The optimal sensitivity is achieved across the 7-10(12) multiplicity ranges for ARCA and in the (7)8-10(12) multiplicity ranges for ORCA, the parentheses indicating that the same sensitivity is reached for both cuts. The final multiplicity range 7-11 is chosen by maximising the overall number of events and excluding the last multiplicity bin (12) where the background estimation is not reliable due to statistical fluctuations.…”

“…A large multi-messenger follow-up campaign will be the key to achieve this goal. The SNEWS2.0 network [12], successor of the SNEWS [13], is also based on the detection of a coincident neutrino signal between experiments all around the world, and it will be enhanced with localisation, time-domain and spectrum studies. The combined false alert rate (FAR) of less than one per century is achieved by requiring a maximum FAR of one per 8 days in each single detector, and the coincidence between two or more detectors within 10 s.…”

“…Typically, the alert message is sent in less than 20 s from the arrival of the corresponding data on-shore. This makes KM3NeT one of the fastest alert sending experiments among the neutrino detectors participating in SNEWS, together with NOνA and HALO [12]. For the currently currently operating ARCA6 and ORCA6 detectors combined, KM3NeT is expected to be sensitive to CCSNe at distances below 11kpc for the 27M progenitor.…”