Millisecond Pulsar Timing in Effelsberg

M. Kramer, O. Doroschenko, A. Jessner, R. Wielebinski
MPIfR, Bonn, Germany

A. Wolszczan
Dept. of Astronomy and Astrophysics, Penn State University, USA

F. Camilo
University of Manchester, NRAL, Jodrell Bank, UK

J. H. Taylor
Physics Department, Princeton University, USA

K. M. Xilouris
NAIC, Arecibo Observatory, Puerto Rico

IAU 160 "Pulsars: Problems and Progress", pp.95

Eds. Johnston, S. Bailes, M. and Walker, M.

We have been observing millisecond pulsars with the 100-m Effelsberg radiotelescope since April 1994. The original objective of this program was to ensure continuity of the millisecond pulsar timing during the upgrade period of the Arecibo telescope. In time, the program has evolved to include timing and polarization measurements of all fast pulsars detectable from Effelsberg. At present, it involves approximately monthly observations of a set of 22 sources. The observations are made with a sensitive dual channel HEMT 21-cm receiver, which has a system temperature of 25 K. The signal is passed through a four channel, 60 x 666 kHz filterbank and then dedispersed in hardware. Pulse arrival times are measured using a hydrogen maser clock which is routinely calibrated with the GPS time signals. The timing analysis involves modeling of pulse arrival times with the widely used TEMPO programme, as well as with the independently developed code called TIMAPR. A high quality of the Effelsberg data is demonstrated by the included examples of pulse shapes and timing residuals. Polarization characteristics of millisecond pulsars observed in this program are described by Xilouris and Kramer (these proceedings).

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