| 25th of July 2018 |
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| ATNF Colloquium |
| Gravitational Dynamics in PSR J1141-6545 |
| by Vivek Venkatraman Krishnan (Swinburne University of Technology) |
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Abstract: Pulsars in relativistic binary systems are natural
laboratories to understand the gravitational dynamics near strongly
gravitating bodies. PSR J1141-6545 is a unique relativistic binary
pulsar composed of a non-recycled pulsar and an older
white-dwarf. Being a gravitationally asymmetric system, it provides a
rare opportunity for testing distinct predictions from alternative
theories of gravity such as scalar-tensor gravity. In this talk, I
will detail the results from the ongoing 18-year old timing campaign
on this pulsar ranging from geodetic precession, through binary
evolution to tests of theories of gravity. I will also touch on future
prospects of better understanding this system with the Ultra wideband
receiver.
The figure above shows the evolution of linear and circular polarization of the pulsar profile of PSR J1141-6545 due to relativistic spin precession. Each line spans 0.6 in pulse phase and the numbers on the right indicate the mean MJD of the observation. The asymmetric evolution of the polarization profile, combined with a flip in the sign of the circular polarization strongly argue towards our line-of-sight crossing the magnetic axis of the pulsar. If true, this provides a rare opportunity for mapping a substantial fraction of a non-recycled pulsar emission beam. |