Astron. Astrophys. 358, 169-176 (2000)

6. Conclusions

The discovery of four sub-mJy pulsars in the limited pilot search observations reported here clearly demonstrate the potential for future pulsar surveys with the Effelsberg radio telescope. As mentioned earlier, the main aim of this survey was to test the feasibility of finding pulsars with a new wide-band search system currently under development. This new system employs narrower channel bandwidths and has much faster sampling rates than presently available; it will therefore have significantly improved sensitivity to short-period, highly dispersed pulsars.

Now that the Parkes multibeam survey is extending its coverage out to (Lyne et al. 2000) there is little to be gained in using the new system at Effelsberg to initiate a large-scale 21-cm search of the Galactic plane. A targeted 21-cm search of globular clusters, however, is a worthy scientific goal since deep (several hour) integrations would achieve a substantially improved sensitivity over previous searches (see e.g. Biggs & Lyne 1996). Such a search would be particularly timely given the flurry of binary pulsar discoveries in a recent 21-cm search of 47 Tucanae (Camilo et al. 2000b).

Another excellent use of the new system would be an 11-cm search for heavily scattered pulsars close to the plane. Such a search would open up an entirely new area of parameter space in Galactic plane searches since it is known that many pulsars discovered at 21-cm are still strongly affected by interstellar scattering. The strong inverse dependence of scattering on observing frequency means that the effects of scattering on an 11-cm search would be an order of magnitude smaller than at 21 cm. In the vicinity of the Galactic centre, where scattering is expected to be greatest (Cordes & Lazio 1997), the best prospects for finding pulsars still seem to be in searches carried out at 5 GHz ( 6-cm), or even higher frequencies (see e.g. Kramer et al. 1996; Kramer et al. 2000).

© European Southern Observatory (ESO) 2000

Online publication: June 26, 2000
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