Pulsars are, in general, very weak sources, typically requiring the addition of several thousand individual pulses with a large radio telescope equipped with sensitive receivers in order to attain a sufficiently large signal-to-noise ratio. The brightest pulsars are, however, strong enough so that individual pulses can be observed. These pulses are known to exhibit great variety in morphology and polarimetric properties from one pulse to the next (see for example Lyne & Smith 1990). It is presently unclear whether the same features in the individual pulses are present at different observing frequencies. One of the current research topics being carried out by EPN is a multi-frequency study of single pulses. The project requires the pulses observed at different telescopes to be time-aligned and thus the format described above has an ideal application in this project. After conversion of the data into this format, the time alignment of the pulses and subsequent statistical analyses is a relatively straight-forward procedure. As an example, a set of pulses from PSR B0329+54 observed simultaneously at Bologna (410 MHz), Jodrell Bank (1.404 GHz) and Effelsberg (4.850 GHz) are shown in Fig. 2 (click here). The pulses show a remarkable similarity at these three frequencies, although counter examples are also observed. Full results of this study will be published shortly.
Figure 2:
Time-aligned single pulses for PSR B0329+54 observed simultaneously
at Effelsberg (4.850 GHz) and Jodrell Bank (1.404 GHz) shown in
the upper panel and at Bologna (410 MHz) and Jodrell Bank (1.404 GHz)
in the lower panel. The data were processed using the EPN format