Further Pulsar Survey and Timing Results for the Globular Cluster 47 Tucanae
C. Robinson (NRAL, Jodrell Bank, University of Manchester, UK),
A. G. Lyne (NRAL, Jodrell Bank, University of Manchester, UK),
R. N. Manchester (ATNF, CSIRO, Australia),
M. Bailes (NRAL, Jodrell Bank, University of Manchester, UK),
N. D'Amico (University of Palermo and IRA - CNR, Bologna, Italy),
S. Johnston (ATNF, CSIRO, Australia)
Abstract Pulsar searches of globular clusters have over the past few years registered more than 30 pulsars in 13 clusters. About a third of these pulsars are located in the globular cluster 47 Tucanae (NGC 104), and were reported in Manchester et al. (1990) and Manchester et al. (1991). They were discovered using the Parkes radio telescope in Australia at an observing frequency of 640 MHz. We have conducted further observations of 47 Tucanae at 640 MHz and at a `new' frequency of 430 MHz, with the aim to search for previously undiscovered pulsars and to perform timing measurements on the known ones. Here, we report the discovery at 430 MHz of the pulsar 47 Tuc N, but withdraw the pulsar 47 Tuc K, earlier reported in Manchester et al. (1991). We present timing solutions for the solitary pulsars 47 Tuc C and D plus updated orbital solutions for the binary pulsars 47 Tuc E and J. Evidence is put forward for the eclipsing nature of the latter pulsar which is believed to be evaporating its companion. A preliminary orbital solution is announced for the binary pulsar 47 Tuc I, which is also argued to be ablating its companion. Finally, an account is presented on the possible origins and evolutions of the 47 Tucanae pulsars, within the framework of current theory.