STATION 04 · MULTI-MESSENGER WIRE DOSSIER High-Energy Neutrino CONFIRMED

IceCube-170922A

“Historical First Neutrino-Blazar Association: 290 TeV Track from TXS 0506+056”

IceCube Neutrino Observatory (South Pole, Antarctica) • Trigger: 2017-09-22 20:54:30 UTC

ASTROPHYSICAL LOCALIZATION & TELEMETRY

FRAME: ICRS / J2000

Sky Coordinates 05h 09m 43.2s +05° 43' 12" (77.43000°, 5.72000°)

Cosmological Redshift z = 0.3365 Luminosity Dist: 4.0 Billion ly (z = 0.3365)

Constellation / Field Orion (TXS 0506+056) Host Field Environment

Detection Significance 3.5σ Astrophysical Association (Historic First) Multi-detector confidence

deposited energy

~290 TeV (Extremely energetic cosmic neutrino)

neutrino energy est

0.5 – 1.0 PeV (Primary parent neutrino)

angular error 50

0.5 deg (90% error radius 0.9 deg)

signalness prob

56.5% (Astrophysical vs atmospheric background)

counterpart

Blazar TXS 0506+056 (BL Lac object)

01 Scientific Overview & Source Physics

On September 22, 2017, IceCube detected a single through-going muon neutrino track with a deposited energy of ~290 TeV. An automated alert was routed worldwide in under 43 seconds. Telescopes following the alert found that the blazar TXS 0506+056 (at z = 0.3365, 4 billion light-years) was undergoing its most energetic gamma-ray flaring state in a decade, marking the first confirmed astrophysical neutrino point source.

02 Multi-Messenger Follow-Up Campaign Matrix

Observatory / Instrument	Spectral Regime	Observational Detection & Counterpart Findings
Fermi LAT	GeV Gamma-ray (0.1–300 GeV)	Identified simultaneous high-state gamma-ray flaring of blazar TXS 0506+056.
MAGIC Cherenkov Telescopes	Very High Energy (> 100 GeV)	Detected VHE gamma rays up to 400 GeV from the blazar over 13-day follow-up campaign.
VLA & OVRO	Radio (15 GHz)	Recorded core radio outburst confirming relativistic jet activity.