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Thousand-Pulsar-Array programme on MeerKAT – VI. Pulse widths of a large and diverse sample of radio pulsars.
- Source :
- Monthly Notices of the Royal Astronomical Society; Dec2021, Vol. 508 Issue 3, p4249-4268, 20p
- Publication Year :
- 2021
-
Abstract
- We present pulse width measurements for a sample of radio pulsars observed with the MeerKAT telescope as part of the Thousand-Pulsar-Array (TPA) programme in the MeerTime project. For a centre frequency of 1284 MHz, we obtain 762 W <subscript>10</subscript> measurements across the total bandwidth of 775 MHz, where W <subscript>10</subscript> is the width at the 10 per cent level of the pulse peak. We also measure about 400 W <subscript>10</subscript> values in each of the four or eight frequency sub-bands. Assuming, the width is a function of the rotation period P , this relationship can be described with a power law with power law index μ = −0.29 ± 0.03. However, using orthogonal distance regression, we determine a steeper power law with μ = −0.63 ± 0.06. A density plot of the period-width data reveals such a fit to align well with the contours of highest density. Building on a previous population synthesis model, we obtain population-based estimates of the obliquity of the magnetic axis with respect to the rotation axis for our pulsars. Investigating the width changes over frequency, we unambiguously identify a group of pulsars that have width broadening at higher frequencies. The measured width changes show a monotonic behaviour with frequency for the whole TPA pulsar population, whether the pulses are becoming narrower or broader with increasing frequency. We exclude a sensitivity bias, scattering and noticeable differences in the pulse component numbers as explanations for these width changes, and attempt an explanation using a qualitative model of five contributing Gaussian pulse components with flux density spectra that depend on their rotational phase. [ABSTRACT FROM AUTHOR]
- Subjects :
- PULSARS
MEERKAT
WIDTH measurement
ACTINIC flux
RADIO measurements
Subjects
Details
- Language :
- English
- ISSN :
- 00358711
- Volume :
- 508
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Publication Type :
- Academic Journal
- Accession number :
- 153718212
- Full Text :
- https://doi.org/10.1093/mnras/stab2775