Parkes observations for project P874 semester 2014APRS_BPSR_01

We propose to perform a directed search for a pulsed radio-emitting counterpart to the rotation-powered 206-ms X-ray pulsar PSR J1640-4631, recently discovered with the NuSTAR X-ray telescope. This source has a very large spin-down rate, and hence is an excellent and rare candidate for the measurement of the source's “braking index,” a fundamental test of the electromagnetic braking hypothesis. A braking index below 2, as has been recently measured for a similar pulsar, would provide further evidence of a connection between pulsars and magnetars. We request time to initially verify this pulsar’s radio detectability, and to perform coherent timing observations that would lead to the aforementioned braking index measurement. If the pulsar is not detected in the initial observations, we will inform the director to withdraw the timing observation portion of our request.