The GECAM Real-time Burst Alert System

Abstract

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM), consisting of two micro-satellites, is designed to detect gamma-ray bursts associated with gravitational-wave events. Here, we introduce the real-time burst alert system of GECAM, with the adoption of the BeiDou-3 short message communication service. We present the post-trigger operations, the detailed ground-based analysis, and the performance of the system. In the first year of the in-flight operation, GECAM was triggered by 42 gamma-ray bursts. The GECAM real-time burst alert system has the ability to distribute the alert within ∼1 minute after being triggered, which enables timely follow-up observations.