Studying the magneto-ionic environment of eclipsing millisecond pulsars

Project Description:

Millisecond pulsars (MSPs) are rapidly spinning neutron stars that emit beams of radio emission from their magnetic poles. With the correct alignment, these radio beams will cross our line of sight periodically as the pulsar spins around its own axis. Sensitive radio telescopes, such as MeerKAT, can pick up pulses from MSPs and measure their time of arrival at the telescope with incredible precision. Of the several hundred known MSPs, the majority of them are found in binary systems, orbiting a companion such as a main sequence star, a white dwarf or even another pulsar. Such binary systems can appear as eclipsing systems from our vantage point: as the pulsar moves behind its companion its emission disappears. Some of these eclipsing systems, the so-called ‘spider binaries’, are in such tight binaries that the surface of the companion star is eroded into a surrounding stellar wind through the blast of the pulsar emission. This typically leads to extended observed eclipse durations, as the pulsar passes behind the stellar outflow of material. By studying the details of the observed eclipses we can infer properties of the companion stellar outflow responsible for obscuring the pulsar emission. We often see for example highly lensed pulses, and rapid changes in the observed dispersion measurement (DM) and rotation measurements (RM). This in turn allows us to estimate the magnetic properties of the ablated companion. In this project the student will analyse MeerKAT Open Time data of an eclipsing spider binary using observing bands (UHF and S-band). The higher the frequency (S-band) the more we peer through the outflow to understand the companion’s properties, and the lower the frequency (UHF) the more we sample the properties of the outflow plasma itself. An improved MeerKAT’s view of this system, will help us build our understanding of the eclipsing mechanisms as well as the evolution and life span of spider binary systems.

Research Area:

Astronomy

Project Level:

Honours

This Project Is Offered At The Following Node(s):

(UCT)