SIMBAD references

Statistical relations are useful tools to comprehend the intrinsic physics processes of gamma-ray bursts (GRBs). In this work we collect spectral lag (τ), variability (V) and optical peak time (t_p,o). We find that there is a correlation between variabilities and spectral lags, reading as V = -0.0075(±0.0007) ×log₁₀ τ+0.0351(±0.0024) . There may also exist a relatively weak positive tendency between GRBs optical band peak times and their spectral time lags. Its Pearson coefficient is 0.398, which indicates a weak linear correlation. If we contain some "negative spectral lag" samples, then the latter relation would be worse due to two outlying points. The τ -V relation is consistent with previous studies, and the positive trend between τ and t_p,o indicates the spectral lag of GRB might be caused by the curvature effect, but this conclusion is not significant.