An analysis of the timing irregularities for 366 pulsars

For completeness we note that it has often been proposed that PSR B0329+59 has planetary companions. Demia´nski & Pr´oszy´nski (1979) and Bailes, Lyne & Shemar (1993) found a three-year periodicity in the timing residuals. However, Shabanova (1995) found no clear evidence for a three-year period, but did present the possibility of a 16.8 yr periodicity. Konacki et al. (1999) argued that there is no evidence for planetary companions. Our data set, which spans 36.5 yr, also shows no evidence for either a 3 yr nor a 16.8 yr periodicity and we believe that the timing noise for PSR B0329+59 has a similar form to the other pulsars in our sample.

Timing noise analyses with large samples of pulsars have been limited by the relatively short data spans studied. Long data-spans have been analysed in a few papers, but for only a small number of pulsars. For instance, Baykal et al. (1999) analysed four pulsars timed for 14 yr. Shabanova (1995) observed PSR B0329+54 for 16 yr, Stairs, Lyne & Shemar (2000) reported on 13 yr of PSR B1828−11 observations and Shabanova, Lyne & Urama (2001) analysed PSR B1642−03 over a 30 yr data span. More recently, the millisecond pulsar PSR J1713+0747 was observed for 12 yr (Splaver et al. 2005) and the young pulsar PSR B1509−58 for 21 yr (Livingstone et al. 2005). Most of the analysis has concentrated on obtaining high quality spectral estimates of the timing residuals or fitting a simple model to the timing residuals of a single pulsar. We note that our sample is 20 times larger than the previous large study of pulsar timing noise (D’Alessandro et al. 1995) in terms of the number of years of rotational history studied.