Speaker
Description
Transient gamma-ray sources are important for understanding the non-thermal universe and the origin of cosmic rays, but their short durations and unpredictable occurrence make them difficult to detect. With its wide field of view, high duty cycle, and broad energy coverage, LHAASO-KM2A is well suited for such searches.
In this work, we perform a systematic search for transient gamma-ray sources using historical valid data from LHAASO-KM2A. Multiple search windows, including 3 minutes, 1 hour, 4 hours, 1 day, 1 week, and 1 month, are adopted to cover different variability timescales. Sliding-window analyses are performed over the full data set. The search is carried out in the energy bands 6.3–25 TeV, 25–100 TeV, and >100 TeV, based on the expected characteristics of extragalactic and Galactic transient sources. Candidate events are evaluated through background estimation, significance calculation, and post-trial selection.
Significant short-timescale signals are found to be associated mainly with GRB 221009A, validating the search method. On longer timescales, several flares from the known active galactic nuclei Mrk 421 and IC 310 are detected. No new transient gamma-ray source is identified.
