Evidence for Gravitational Lensing of GRB 200716C

Observationally, there is a small fraction of gamma-ray bursts (GRBs) with prompt emission observed by Fermi/GBM that are composed two pulses. Occasionally, the distance to GRB may be lensed when high mass astrophysical object resides in path between source and observer. In this paper, we describe 200716C, which has two-pulse duration few seconds. We present Bayesian analysis identifying gravitational lensing both temporal spectral properties, calculate time delay (Δt ∼ 1.92 s) magnification (γ 1.5) those pulses based on fits. One can roughly estimate lens about 2.4 × 105M⊙ rest frame. also false alarm probability for detection 0.07% trial factors, present-day number density 808Mpc−3 an energy Ω 1.4 10−3. If first pulse near trigger indeed gravitationally echoed second pulse, 200716C short candidate extended emission.