From 7091c7ca0d15e71e3998420bad023c78758694c8 Mon Sep 17 00:00:00 2001 From: Feifei Huang <fhuang@km3net.de> Date: Sat, 10 Oct 2020 02:38:22 +0200 Subject: [PATCH] Update Multimessenger.md --- pages/Multimessenger.md | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/pages/Multimessenger.md b/pages/Multimessenger.md index 3509a9a..fa1d719 100644 --- a/pages/Multimessenger.md +++ b/pages/Multimessenger.md @@ -24,12 +24,16 @@ Because neutrinos travel with nearly the speed of the light, a real time or near ## KM3NeT Multi-Messenger Neutrino Alerts -* For the search of MeV core-collapse supernova neutrinos, each KM3NeT optical module acts as a detector, each comprising of 31 PMTs. A CCSN neutrino interaction leads to higher counting rates of individual PMTs and an increase of the number of coincident hit PMTs in the same optical module. Its search entails a different method from the usual neutrino event reconstruction route, and it has a separate alert system called the SuperNova Early Warning System (https://snews.bnl.gov/), so the KM3NeT supernova alerts is not discussed in here. KM3NeT is already connected to SNEWS. +KM3NeT is a multi-purpose cubic-kilometer neutrino observatory currently being deployed at the bottom of the Mediterranean Sea. The detector is 3-d arrays of light sensors called digital optical modules (DOMs), each DOM consist of 31 PMTs that are able to detect light signals. KM3NeT detects neutrinos via the Cherenkov technique: neutrinos have weak interactions in the seawater and produce secondary particles which emit Cherenkov light while traveling in the seawater with a speed larger than the light phase speed in seawater. So even though neutrinos are not directly observed, the spatial and temporal distributions of the light and the amount of light observed by the DOMs can be used to reconstruct the incoming neutrinos' direction and energy. -* For the search of higher energy neutrinos, such as astrophysical neutrinos, KM3NeT will be able to send/receive alerts from/to the multi-messenger community: +KM3NeT consists of two detectors: ORCA (Oscillation Research with Cosmics in the Abyss) and ARCA (Astroparticle Research with Cosmics in the Abyss). ARCA's 3-d arrays will instrument 1 Gton of seawater, with the primary goal of detecting cosmic neutrinos with energies between several tens of GeV and PeV. Due to its position in the Northern Hemisphere, ARCA will provide an optimal view of the Southern sky including the Galactic Center. ORCA arrays are denser and its volume is smaller ( ~ few Mtons), optimized for the detection of atmospheric neutrinos in the 1 - 100 GeV. KM3NeT can also study low-energy neutrino astronomy, such as MeV-scale core-collapse supernova, where each KM3NeT DOM acts as also as a detector. + +* For the search of neutrinos via event reconstructions based on (causally coincient) lit-up DOMs, focusing on high energy neutrinos, such as astrophysical neutrinos, KM3NeT will be able to send/receive alerts from/to the multi-messenger community: 1. to receive external alerts, i.e. alerts generated by external experiments (e.g. gravitatinal waves alerts from LIGO/Virgo, neutrino alerts from other neutrino experiments) via GCN https://gcn.gsfc.nasa.gov/) and conduct search for correlated neutrinos in KM3NeT. 2. to send neutrino alerts (to GCN) that we observe in KM3NeT, including multiplet alerts, possible astrophysical neutrinos, any correlated neutrinos we find in the above correlation search. The alerts will be used for external experiments to conduct their correlation search/follow-up. +* For the search of MeV core-collapse supernova neutrinos, each KM3NeT DOM acts as a detector. A CCSN neutrino interaction leads to higher counting rates of individual PMTs and an increase of the number of coincident lit-up PMTs in the same optical module. Its search entails a different method from the usual neutrino event reconstruction route, and it has a separate alert system called the SuperNova Early Warning System (https://snews.bnl.gov/), so the KM3NeT supernova alerts is not discussed in here. KM3NeT is already connected to SNEWS. + ### KM3NeT Alert Types The planned alert types include: -- GitLab