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PSR J1022+1001: profile stability and precision timing


Hotan, AW and Bailes, M and Ord, SM, PSR J1022+1001: profile stability and precision timing, Monthly Notices of the Royal Astronomical Society, 355, (3) pp. 941-949. ISSN 0035-8711 (2004) [Refereed Article]

DOI: doi:10.1111/j.1365-2966.2004.08376.x


We present an investigation of the morphology and arrival times of integrated radio pulses from the binary millisecond pulsar PSR J1022+1001. This pulsar is renowned for its poor timing properties, which have been postulated to originate from variability in its average pulse profile. Although a subclass of long-period pulsars is known to exhibit mode changes that give rise to very large deviations in their integrated profiles, this was the first millisecond pulsar thought to have an unstable mean profile. As part of a precision timing programme at the Parkes radio telescope, we observed this pulsar between 2003 January and 2004 March using a coherent de-dispersion system (the Second Caltech Parkes Swinburne Recorder). A study of morphological variability during our brightest observations suggests that the pulse profile varies by at most a few per cent, similar to the uncertainty in our calibration. Unlike previous authors, we find that this pulsar times extremely well. In 5-min integrations of 64-MHz bands, we obtain a weighted rms residual of just 2.27 μs. The reduced χ2 of our best fit is 1.43, which suggests that this pulsar can be timed to high accuracy with standard cross-correlation techniques. Combining relativistic constraints with the pulsar mass function and consideration of the Chandrasekhar mass limit on the white dwarf companion, we can constrain the inclination angle of the system to lie within the range 37° < i < 56°. For reasonable pulsar masses, this suggests that the white dwarf is at least 0.9 M⊙. We also find evidence for secular evolution of the projected semimajor axis.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Galactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Hotan, AW (Dr Aidan Hotan)
ID Code:45114
Year Published:2004
Web of Science® Times Cited:25
Deposited By:Physics
Deposited On:2007-07-03
Last Modified:2007-07-03

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