2026/01/17 by Run-Chao Chen, Jun Yang, Yi-Han Iris Yin +1 · 1 voice · 1 citation
Physics and Astronomy · #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/ae3a96
Coherent oscillations at kilohertz frequencies have recently been detected in a small number of gamma-ray bursts (GRBs), suggesting quasi-periodic dynamics in their central engines. A prominent example is GRB~230307A, which exhibited a brief, highly coherent, energy-dependent periodic signal interpreted as the possible spin signature of a nascent millisecond magnetar formed after a compact binary merger. Motivated by these developments, we conducted a comprehensive search for similar signals, accounting for both temporal and spectral dependencies, in 532 short GRBs with time-tagged event data recorded by the Burst and Transient Source Experiment (BATSE) onboard the Compton Gamma-Ray Observatory. Within this sample, we identify a single statistically significant case: GRB~960616 (BATSE trigger~5502), in which the ∼30~ms main emission episode is coherently modulated at 1100~Hz, with the strongest modulation above 320~keV and a fractional amplitude of ∼47%. Assuming the presence of a coherent periodic modulation, we use data-driven Monte Carlo simulations to place an upper limit of ∼8% on the fraction of the total radiated energy that can be modulated by the QPO. This event, exhibiting a periodicity at ∼0.91~ms, further supports the possibility that millisecond periodicities can arise during GRBs in merger-driven scenarios.