Abstract
We present long-term timing observations of four millisecond radio pulsars with the 305 m Arecibo and the 100 m Effelsberg radiotelescopes. Our analysis of the combined pulse time-of-arrival data from the two telescopes has led to improvements of the precision of timing parameter determination for all the four pulsars. A new, much more significant measurement of a third-order spin frequency derivative of PSR B1257 + 12 adds to the existing evidence that a fourth, distant planet may orbit this pulsar. Proper motions have been measured for PSR J1640 + 2224, PSR B1953 + 29, and PSR J2229 + 2643. The derived low transverse velocities of these objects agree with the kinematic characteristics of the observed millisecond pulsar population. Exceptionally low spindown rates of PSR J1640 + 2224 and PSR J2229 + 2634 have been used to derive useful limits on the initial spin periods of these objects and on the variation of the gravitational constant G.
Original language | English (US) |
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Pages (from-to) | 907-912 |
Number of pages | 6 |
Journal | Astrophysical Journal |
Volume | 528 |
Issue number | 2 PART 1 |
DOIs | |
State | Published - Jan 10 2000 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science