High-Energy Neutrino Follow-up at the Baikal-GVD Neutrino Telescope

The Baikal-GVD deep underwater neutrino experiment participates in the international multi-messenger program to detect the astrophysical sources of high- and ultrahigh-energy cosmic-ray particles, being at the stage of array deployment and a step-by-step increase of the telescope’s effective volume to the scale of a cubic kilometer. At present, the telescope consists of seven clusters containing 2016 photodetectors. The effective volume of the detector has reached 0.35 km $${}^{3}$$ for the selection of shower events from neutrino interactions in Baikal water. The experimental data have been accumulated in a continuous exposure mode since 2015, allowing a prompt data analysis and a celestial-sphere monitoring program to be implemented in real time. We discuss the structure of the data acquisition system, describe the physical event reconstruction procedure in the mode of fast response to alerts, and present the results of our analysis of nine alerts from the polar IceCube telescope from early September to late October 2020.