Probing pulsar scattering between 120 and 280 MHz with the MWA. (arXiv:1903.02087v1 [astro-ph.HE])

Probing pulsar scattering between 120 and 280 MHz with the MWA. (arXiv:1903.02087v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Kirsten_F/0/1/0/all/0/1">F. Kirsten</a> (Chalmers University), <a href="http://arxiv.org/find/astro-ph/1/au:+Bhat_N/0/1/0/all/0/1">N. D. R. Bhat</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Meyers_B/0/1/0/all/0/1">B. W. Meyers</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Macquart_J/0/1/0/all/0/1">J.-P. Macquart</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Tremblay_S/0/1/0/all/0/1">S. E. Tremblay</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Ord_S/0/1/0/all/0/1">S. M. Ord</a> (CSIRO)

The high sensitivity and wide frequency coverage of the Murchison Widefield
Array allow for the measurement of the spectral scaling of the pulsar
scattering timescale, $alpha$, from a single observation. Here we present
three case studies targeted at bright, strongly scattered pulsars J0534+2200
(the Crab pulsar), J0835-4510 (the Vela pulsar) and J0742-2822. We measure the
scattering spectral indices to be $-3.8pm0.2$, $-4.0pm1.5$, and $-2.5pm0.6$
for the Crab, Vela, and J0742-2822, respectively. We find that the scattered
profiles of both Vela and J0742-2822 are best described by a thin screen model
where the Gum Nebula likely contributes most of the observed scattering delay.
For the Crab pulsar we see characteristically different pulse shapes compared
to higher frequencies, for which none of the scattering screen models we
explore are found to be optimal. The presence of a finite inner scale to the
turbulence can possibly explain some of the discrepancies.

The high sensitivity and wide frequency coverage of the Murchison Widefield
Array allow for the measurement of the spectral scaling of the pulsar
scattering timescale, $alpha$, from a single observation. Here we present
three case studies targeted at bright, strongly scattered pulsars J0534+2200
(the Crab pulsar), J0835-4510 (the Vela pulsar) and J0742-2822. We measure the
scattering spectral indices to be $-3.8pm0.2$, $-4.0pm1.5$, and $-2.5pm0.6$
for the Crab, Vela, and J0742-2822, respectively. We find that the scattered
profiles of both Vela and J0742-2822 are best described by a thin screen model
where the Gum Nebula likely contributes most of the observed scattering delay.
For the Crab pulsar we see characteristically different pulse shapes compared
to higher frequencies, for which none of the scattering screen models we
explore are found to be optimal. The presence of a finite inner scale to the
turbulence can possibly explain some of the discrepancies.

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