AMON: Multimessenger Alerts from High-Energy Gamma Rays and Neutrinos

Abstract

The Astrophysical Multimessenger Observatory Network (AMON) has been working to link the world's high-energy and multimessenger observatories together into a single network in order to evoke discovery of multimessenger sources, exploit these sources for purposes of astrophysics, fundamental physics, and cosmology, and explore project datasets for evidence of multimessenger source populations. AMON has been working to commission multiple multimessenger alert streams, including gravitational wave + gamma-ray (GW+$\gamma$) and high energy neutrino + gamma-ray ($\nu$+$\gamma$) coincidence alerts. One such $\nu$+$\gamma$ alert stream, now in an advanced stage of development, will search in near real-time for statistically-rare coincidences between $\sim$TeV gamma-rays observed by the High-Water Altitude Cherenkov Observatory (HAWC) and $\geqslant$TeV neutrinos detected by the IceCube Neutrino Observatory. We describe the statistical design, calibration, and validation of these HAWC and IceCube $\nu$+$\gamma$ alerts, which will be commissioned soon and made available to AMON follow-up partners under terms of the AMON MoU. With a median delay to alert distribution of six hours and angular uncertainties of $\leqslant$1\arcdeg, the alerts should be well-suited for deep electromagnetic follow-up observations.