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Fig. 4


A sample of average pulse profiles from LOFAR observations of various pulsars made during the commissioning period. The dark line corresponds to LOFAR observations made with the HBAs with 48 MHz of bandwidth, divided into 3968 channels, at a central frequency of 163 MHz. Typically about 12 stations were used and they were combined incoherently. The abcissa is the rotational phase and at present there is no flux calibration for the LOFAR data, hence no flux scale is shown. The majority of the observations are  ~1000 s in duration, except for PSR B1257+12, which was observed for 3 h. The dispersion measure smearing is less than two bins for the majority of the pulsars shown; if the smearing is large, this is indicated by a bar on the left hand side. The lighter line corresponds to observations made at 1408 MHz by Gould & Lyne (1998) except for the observations of PSR B0943+10 which was at 608 MHz and PSR B1237+25 which was at 1600 MHz (from van Hoensbroech & Xilouris 1997). All archival profiles are from the EPN database (; they are shown for illustration purposes and are manually aligned. Both the LOFAR and EPN profiles have been normalised to the peak intensity. The periods are given in seconds and the dispersion measures in pc cm-3.

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