MULTI-MESSENGER EVENTS

This tool shows public multi-messenger events from gravitational waves and neutrinos, displays their probability footprints on the sky and provides access to the data. Currently, ESASky provides access to multi-messenger events from the following observatories:

 

Gravitational Waves

The Gravitational Waves tab displays a list of the gravitational wave events detected by Advanced LIGO and Advanced Virgo from observing run 3 (O3) and by the LIGO-Virgo-KAGRA collaboration's 4th observing run (O4). Click on a gravitational wave event to go to the centre of the associated footprint. A solid line shows the 50% confidence contours and a dashed line the 90% confidence contours. The probability map is also shown. The probability map and contours are extracted from the data available in the GCN webpage, without including the rejected ones. We use the files LALinference when available and Bayestar. For more information visit the LIGO collaboration and Virgo collaboration webpages and the Gravitational-Wave Candidate Event Database (GraceDB) webpage.

ESASky displays the following columns for the gravitational wave events detected by Advanced LIGO and Advanced Virgo in the O3 data (more columns are available via the settings button or by right clicking in the table):

LIGO/Virgo Gravitational Wave events columns displayed in ESASky
Column name Units Description
Event Page - Event page
Alert Type - VOEvent alert type
Grace ID - Identifier in GraceDB
ISO Time YYYY-MM-DD dd:mm:ss.s Timestamp for detection of this gravitational wave event 
FAR Hz False Alarm Rate for GW candidates with this strength or greater
Instruments - List of instruments used in analysis to identify this event
Pipeline - Low-latency data analysis pipeline
BBH - Pobability that the source is a binary black hole (both objects heavier than 5 Msolar)
BNS - Probability that the source is a binary neutron star (both objects lighter than 3 Msolar)
NSBH - Probability that the source is a neutron star - black hole merger (primary heavier than 5 Msolar, secondary lighter than 3 Msolar)
Mass Gap - Probability that the source has at least one object between 3 and 5 Msolar
Has NS - Probability that at least one object in the binary has a mass that is less than 2.83 Msolar 
Has Remnant - Probability that a nonzero mass was ejected outside the central remnant object
Terrestrial - Probability that the source is terrestrial (i.e. a background noise fluctuation or a glitch)
Fluence erg cm-2 Estimated fluence of GW burst signal 
Central Freq Hz Central frequency of GW burst signal
Duration s Measured duration of GW burst signal
Sky Map - Sky Map fits

 

 

Neutrino Events

The Neutrinos tab displays a list of the Neutrino event candidates detected by the IceCube Neutrino Observatory and reported to GCN (Gamma-ray Coordinates Network)/AMON Notices. Gold, Bronze and Cascade candidate events are displayed and the list is automatically updated when new events are reported in the GCN Notices. Gold and Bronze events are single-neutrino events in the IceCube detector with a neutrino energy between sub-PeV to 1 PeV. Gold events are on average ~50% likely to be of astrophysical origin and Bronze events are on average ∼30% likely to be of astrophysical origin. Cascade events are triggers from high energy neutrinos.

When the Neutrino tab is selected, all IceCube Neutrino candidate events are listed and the footprints are displayed on the sky. The footprints are the location uncertainty (a radius, statistical plus systematic, 90% containment. The 'Src Error' column, or the 'Error90' column in the GCN/AMON). Click on the 'Go to' button to centre on each event and the 'Event Page' to view the GCN/AMON notice for each event. For more information visit the IceCube Neutrino Observatory and the GCN/AMON webpages.

ESASky displays the following columns for the Neutrino candidate events detected by the IceCube Neutrino Observatory (more columns are available via the settings button or by right clicking in the table):

IceCube Neutrino event columns displayed in ESASky
Column name Units Description
Event Page - Event page
Notice Type - Notice Type (Gold and Bronze events are single-neutrino events in the IceCube detector with a neutrino energy in the sub-PeV to 1 PeV. Gold events are at least ~50% likely to be of astrophysical origin, Bronze events are at least ∼30% likely to be of astrophysical origin. Cascade events are triggers from high energy neutrinos).
Event - Event number
Run - Run number
Ra hh mm ss.ss  RA location of the event (J2000 epoch)
Dec dd mm ss.ss  Dec location of the event (J2000 epoch)
Energy TeV For Gold and Bronze events: most probable neutrino energy that would have produced an event with these observed parameters under an astrophysical neutrino signal hypothesis, assuming the best-fit diffuse muon neutrino astrophysical power-law flux ( E^-2.19). For Cascade events: Energy of the neutrino (in TeV).
Signalness - Probability this is an astrophysical signal relative to backgrounds.
Stream - Stream number
FAR - False Alarm Rate. For Gold and Bronze events: the rate of background events expected that are 'like this alert' that would be seen by IceCube per year. For Cascade events: specifies how often a trigger of this intensity would happen from just noise fluctuations (an identically 0 value means it was not calculated TBD).
Discovery Timestamp YYYY-MM-DD dd:mm:ss.s Timestamp for detection of this Neutrino candidate event