Speaker
Description
The double pulsar binary system (J0737$-$3039A/B) is a gold-standard laboratory for testing general relativity in the strong field regime, and as such has been the target of pulsar timing campaigns for over 20 years. Yet, despite the system's high profile within and outside of the pulsar community, there have been very limited observations below 300 MHz. Past observing campaigns above 800 MHz have studied scintillation in detail, identifying a single dominant scattering screen likely associated with the Gum nebula. However, to date, no direct measurements have been made of the timescale or frequency scaling of pulse broadening at low frequencies, which can provide independent constraints on the properties of the scattering medium. Such measurements are of interest both for understanding the interstellar medium and improving precision in future timing observations. We have performed four targeted observations of the double pulsar with the MWA in a distributed channel configuration spanning 110 to 230 MHz. These observations have allowed us to make simultaneous measurements of pulse broadening over a ~70% fractional bandwidth on epochs separated by 1 month to over 1 year. I will present these results, along with other results from these observations including constraints on the flux density spectrum.
| Timeslot preferences | 15min + questions |
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