3. Data analysis
3.1. Bandwidth and duration
As mentioned above, this type IV-DCIM was also recorded over the range of 800-2000 MHz, which means that it had a bandwidth of more than 2.0 GHz, since it was beyond 3.80 GHz high frequency limit of the BAO spectrometer. It lasted for more than one hour (67 minutes), and had a long decay phase (about 60 minutes); near the intensity peak (around 05:48:12 UT) a peculiar fine structure was detected. This fine structure with a negative picture (Fig. 2 bottom panel) had a bandwidth about 430 MHz between 2.74 GHz and 3.17 GHz, and a total duration over 1.3 seconds.
3.2. Frequency drift and polarization
Fig. 3 shows the average drifting rates of the four branches. The branches of the first U have bigger rates than those of the second one. In addition, as given in Fig. 1, the type IV-DCIM and the fine structure were almost unpolarized all time.
© European Southern Observatory (ESO) 2000
Online publication: January 29, 2001