Speaker
Description
Identifying the sources of ultra-high-energy particles is inherently a multimessenger problem, requiring cosmic rays, photons, neutrinos, and gravitational waves to establish robust source associations and physical interpretations. The Pierre Auger Observatory in Malargüe, Argentina, combines a 3,000 km$^2$ surface array of 1,660 surface detector units with 27 fluorescence telescopes, enabling precise hybrid reconstruction up to $10^{20}$ eV. Auger is also sensitive to ultra-high-energy neutrinos and photons: neutrinos are identified in very inclined down-going and Earth-skimming channels using the time structure of surface-detector signals, while photons are selected via the characteristically muon-poor development of electromagnetic showers. We review recent results, including updated diffuse and targeted limits on photons above 1 EeV and neutrino searches with exposure dominated by the Earth-skimming channel. We summarize time- and direction-coincident follow-ups of LIGO–Virgo compact-binary mergers, including photon searches over 91 GW events and stacked neutrino searches over 93 BBH mergers, yielding no candidates and constraining ultra-high-energy emission. Finally, we outline Auger low-latency alerts to AMON (distributed via GCN) and prospects with AugerPrime for improved mass tagging and enhanced photon/neutrino discrimination.
| I read the instructions above | Yes |
|---|