An Observational Study of the Strong Single Pulses of PSR J0034-0721

摘要

Using the 25m radio telescope of the Urumqi Observatory, the strong single pulses of the pulsar PSR J0034-0721 were observed at 1.54GHz on 6th Aug. 2007. With the technique of single-pulse detection, 116 single pulses with the signal-to-noise ratios of R_(SN)≥5 were detected from the observed data of 1h. At 1.54GHz, the signal-to-noise ratios of the detected single pulses are in the range from 5 to 10.5, and the peak flux densities of these pulses are approximately 14～29 times that of the average pulse (AP), much less than the ratios between the intensities of typical giant pulses and the intensity of AP. The cumulative distribution of the intensities of these pulses is basically a powerlaw distribution with the spectral index α=-4.3±0.4. The detection rates for the pulses of R_(SN)≥5 and R_(SN)≥10 are 3% and 0.08%, respectively. For these pulses, the half-peak width W_(50) ranges from 1.6ms to 8ms, 3.9ms in average. The phases of the vast majority of the strong single pulses are concentrated around the peak position of AP, but 2 strong pulses of R_(SN)≥8.5 are detected at the phases about 33ms earlier than the phase of the AP peak. This implies that there probably exist two emission regions of strong pulses, and this is consistent with the previously observed results at 40MHz and 111MHz, except that at 1.54GHz the profile of AP exhibits only one component.