Timing noise analysis of 27 HartRAO radio pulsars A. E. Chukwude

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A. E. Chukwude




Author: A.E. Chukwude

Timing observations on 27 radio pulsars obtained at Hartebeesthoek Radio Astronomy Observatory' (HanRAO) between 1984 and 1999 were analyzed in order to provide an in-depth empirical description of continuous, random rotational fluctuations in radio pulsars. The results of the detailed tinte-domain analyses, which are based on the strength parameter and structure function techniques, show that (i) the observed rotational fluctuations in five pulsars are apparently too weak to allow for any nteaningful timing noise analysis; (ii) the timing activity of most (> 60%) of the remainder of 22 pulsars cannot be explained in terms ofsimple idealized randont walk processes only and (iii) the observed timing activity of three, three, and two objects are characterised by rotational fluctuations whose statistics appear consistent with random walks in pulse phase, pulse frequency and slowing down rate, respectively. We discuss the results in the framework of the current understanding of radio pulsar timing noise phenomenology.


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A. E. Chukwude, University of Nigeria, Nsukka, Enugu State

Department of Physis & Astronomy


Alpar: M.A. Langer, S.A. •and Sauls, J.A. (1984). Rapid postglitch spin-up of the superfluid core in pulsars. ApJ, 282, pp.533-541

Alpar, M.A., Chau, H.F., Cheng, K.S. and Pines, D. (193). Postglitch relaxation of VELA pulsar after its first eight large glitches, ApJ, 409, pp.345-349

Arzoumanian, Z., Joshi, K. , Rasio, F. , Thorsett, S.E. (1996). Orbital parameters of the PSR 1620-26 triple system.ln: Johnston, S., Walker, M.A. and Bailes, M (ed) IAU Colloquium Pulsars: problems and Progress. Astronomical society of the Pacific 160, 525

Boynton, P.E., Groth, E.J., Hutchinson, D.P., et al. (1972). Optical timing of the Crab pulsar, NP0532. ApJ, 175, pp.217-242.

Burgay, M. D'Amico, N. , Possenti, A. , et al. (2003). An increased estimate of the merger rate of double neutron stars from observations of a highly relativistic system. Nature, 426, pp. 531-533

Chukwude, A.E. (2002). A study of timing noise in radio pulsars. PhD thesis, University of Nigelia, Nsukka

Chukwude, A.E. (2003). On the statistical implication of timing noise for pulsar braking index. 406, pp.667-671

Chukwude, ASE. (2007). A statistical analysis of radio pulsar timing noise. ChJAA, 7, pp.521530

Chukwude, A.E. and Buchner, S. (2010). Evidence for magnetic axis re-orientation in the pulsar B0959-54. MNRAS. in press Chukwude, A.E., UbachukWu, A.A. and Okeke, P.N. (2003). Periodicities in rotation and DM of PSR B1557-50. A&A, 399, pp.231-235

Chukwude, A.E. and Urama, J.O. (2010). Observations of microglitches in HartRAO radio pulsars. MNRAS. in press

Cordes, J.M. (1980). Pulsar timing Il Analysis of random walk timing noise — Application to Crab pulsar ApJ, 237, pp.216-226

Cordes, J.M. (1993). The detectability of planetary companions in radio pulsars. In: Phillips, J.A., Thorsett, S.E. and Kulkarni, S.R. (ed) ASP Conf. Ser. 36, Planets Around Pulsars, pp.43-60

Cordes, J.M. and Downs, G.s, (1985). JPL pulsar timing observations Ill. Pulsar rotation fluctuations. ApJS, 59, pp.343-382

Cordes, J.M., Downs, G.S. and Krauss-Polstorff, J. (1988). JPL pulsar timing observations IV. Macro and microjumps in the VELA pulsar 0833-45. ApJ, 330, pp.847-869

Cordes, J.M. and Greenstein, G. (1981). Pulsar timing IV — Physical models for timing noise processes. ApJ, 245, pp. 1060-1079

Cordes, J.M. and Heifand, D.J. (1980). Pulsar timing Ill — Timing noise of 50 pulsars. ApJ, 239, pp.640-650

D'Alessandro, F., McCulloch, P.M., Hamilton, P.A. and Deshpande, A.A. (1995). The timing noise of 45 southem pulsars.

MNRAS, 277, pp. 1033-1046

Faulkner, A.J., Kramer, M. and Lyne, A.G. et al (2004). Parkes multibeam pulsar survey V — Finding binary and millisecond pulsars. MNRAS, 355, pp. 147-158

Flanagan, C.S. (1990). Rapid recovery of the VELA pulsar from a glitch. Nature, 345, —417

Flanagan, C.S. (1995). Glitch observations in pulsars 0833-45 and 1641-45. PhD thesis, Rhodes University Grahamstown, South Africa

Goldreich, P. and Julian, W.H. (1969). Pulsar electrodynamics. ApJ, 157, pp.869-871

Hobbs, G., Lyne, A.G. and Kramer, M. (2006). Pulsar timing noise. ChJAA suppl. 2, pp. 169175

Hobbs, G. , Lyne, A.G. and Kramer, M. et al (2004). Long-term timing observations of 374 pulsars. MNRAS, 353, pp. 1311-1344

Kramer, M., Bell, J.F. Manchester, R.A. et al. (2003). MNRAS, 342, pp. 1299-1305

Lindsey, W.C. and Chie, C.M. (1976). Theory of oscillator instability based upon structure functions. Proc. IEEE, 64, pp. 1652-1666

Lorimer, D., Kramer, M. (2005). Handbook of pulsar Astronomy (Cambridge University Press)

Lyne, A.G., Graham-smith, F. (1998). Pulsar Astronomy (Cambridge University Press)

Lyne, A.G., Shemar, S.L. and Graham-Smith, F. (2000). Statistical studies of pulsar glitches MNRAS, 315, pp.534-542

Manchester, R.N. and Taylor, J.H. (1977). Pulsars (San Francisco: Freeman)

McCulloch, P.M. Hamilton, P.A., McConnell, D. and King, E.A. (1990). The VELA glitch of Christmas 1988. Nature, 346, pp822-824

Rudeman, M., Zhu, T. and Chen, K. (1998). Neutron star magnetic field evolution, crust movement and glitches. ApJ, 492, pp.267280

Rutman, J. (1978). Characterization of phase and frequency instabilities in precision frequency sources — fifteen years of progress. Proc IEEE, 66,pp.1048-1075

Shabanova, T.V. , Lyne, A.G. and Urama, J.O. (2001). Evidence for free procession in the pulsar B 1642-03. ApJ, 552, pp.321-325

Stairs, I.H., Lyne,A.G. and Shemar, L.S. (2000). Evidence for free procession in a pulsar.Nature. 406. pp.484-486

Stairs, I.H., Manchester, R.N., Lyne, A.G. et al. (2001). PSR J1740-3052: A pulsar with a massive companion. Nature, 325, pp.979-988 Wang, N. , Wu, X., Manchester, R.N., et al. (2001). A large glitch in the Crab pulsar. ChJAA 3, pp.195-199

Weisberg, J.M. and Taylor, J.H. (2002). General relativistic geodetic spin procession in binary pulsar B1913+16: Mapping the emission beam in two dimensions. ApJ, 576, pp.942949

Wolszczan, A. (1994). Confirmation of Earthmass planets orbiting the millisecond pulsar PSR B1257-12. Science, 264, pp.538-542