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Figure 1: Data from GRB 990308 with z=1.60 collected by BATSE trigger 7457 in a total number of 211 64 ms bins in the energy band 115-320 keV (top panel), and its Symmlet-10 (Mallat 1998) discrete wavelet transform (DWT) at the level L=6. The horizontal axis corresponds to the same time scale as in the original burst. Each level on the vertical axis shows the wavelet coefficients at a given resolution level (i.e., scale). The wavelet coefficients are represented by spikes whose size and direction (up or down) is determined by the magnitude and sign (+ or -) of the coefficient. |
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Figure 2: The GRB 990308 light curve after preprocessing which sets the median absolute deviation of wavelet coefficients at the fine scale equal to unity, as described in more detail in Appendix A. The intensity profile estimated by the wavelet shrinkage procedure at the level L=6 is presented in the bottom panel. |
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Figure 3:
The CWT image (middle panel) of the GRB 990308 intensity profile (top
panel). The horizontal and vertical axes give, respectively, the position u and ![]() |
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Figure 4: The light curve for GRB 990308 obtained by BATSE with trigger 7457, binned with 64 ms resolution in four spectral bands. |
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Figure 5:
The estimated intensity profiles of GRB 990308 - see Fig. 4 -
obtained in four spectral bands by using a Symmlet-10 (Mallat 1998) basis
at level L=6. The signal-to-noise ratios are at the levels
SNR1=23.07,
SNR2=22.71,
SNR3=23.58 and
SNR4=23.87 for each band, respectively.
All variation points founded by CWT zoom are marked by circles. The
behaviours of the Lipschitz exponents ![]() |
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Figure 6:
Spectral time lags between the arrival times of pairs of genuine variation
points detected in the third and first BATSE spectral bands. The
analysis has been done for 9 GRB light curves collected with time
resolution 64 ms. The solid line shows the best linear fit versus ![]() |
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Figure 7: The combination of 64 ms BATSE time-lag measurements shown in Fig. 6 with the measurement obtained from the BATSE-OSSE comparison and the TTE portion of the GRB 980329 light curve, with resolution 2.7 ms. |
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Figure 8:
The ![]() |
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Figure 9:
The same ![]() |
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