The Thousand-Pulsar-Array programme on MeerKAT – V. Scattering analysis of single-component pulsars
Autor: | M. Serylak, Ryan Shannon, Bettina Posselt, Aris Karastergiou, Simon Johnston, S. Buchner, Matthew Bailes, W. van Straten, R. Spiewak, Michael Kramer, Daniel J. Reardon, Michael Keith, L. S. Oswald, M. Geyer, Aditya Parthasarathy, V. Venkatraman Krishnan |
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Rok vydání: | 2021 |
Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Spectral index Line-of-sight 010308 nuclear & particles physics Scattering Gaussian Isotropy FOS: Physical sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Standard deviation law.invention Telescope symbols.namesake Pulsar Space and Planetary Science law 0103 physical sciences symbols Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics |
Zdroj: | Monthly Notices of the Royal Astronomical Society. 504:1115-1128 |
ISSN: | 1365-2966 0035-8711 |
Popis: | We have measured the scattering timescale, $\tau$, and the scattering spectral index, $\alpha$, for 84 single-component pulsars. Observations were carried out with the MeerKAT telescope as part of the Thousand-Pulsar-Array programme in the MeerTime project at frequencies between 0.895 and 1.670 GHz. Our results give a distribution of values for $\alpha$ (defined in terms of $\tau$ and frequency $\nu$ as $\tau\propto\nu^{-\alpha}$) for which, upon fitting a Gaussian, we obtain a mean and standard deviation of $\langle\alpha\rangle = 4.0 \pm 0.6$. This is due to our identification of possible causes of inaccurate measurement of $\tau$, which, if not filtered out of modelling results, tend to lead to underestimation of $\alpha$. The pulsars in our sample have large dispersion measures and are therefore likely to be distant. We find that a model using an isotropic scatter broadening function is consistent with the data, likely due to the averaging effect of multiple scattering screens along the line of sight. Our sample of scattering parameters provides a strong data set upon which we can build to test more complex and time-dependent scattering phenomena, such as extreme scattering events. Comment: Accepted for publication in MNRAS. 14 pages, 14 figures, 2 tables |
Databáze: | OpenAIRE |
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