Project Overview

Ever since their monumental discovery in 1967, pulsars have been amongst the most highly valued astronomical objects. These cosmic lighthouses emanate intense beams of electromagnetic radiation from their (magnetic) poles and they captivate public interest and attention. Their role in advancing fundamentals of physics and astrophysics has been undeniable. Pulsars have proven to be versatile tools in furthering our understanding of fundamentals of physics, from nuclear to cosmological scales. Astonishingly, the physical processes that govern the emission of electromagnetic radiation from these exotic stars still eludes us - the pulsar radio emission mechanism remains an outstanding problem in modern astronomy.  

This is in part to do with the inherent complexity of the problem, which involves application of relativistic plasma physics under extreme physical conditions. For many years, the investigation predominantly focused on in-depth studies of individual objects or some specific phenomena, and looking for common trends in the larger pulsar population. The past couple of decades have seen a resurgence of low-frequency telescopes, development of wide-band instrumentation, and the emergence of multiple major radio astronomy facilities in the lead up to the Square Kilometre Array (SKA) – the largest and most sensitive radio telescope in the world, currently under construction in Western Australia and South Africa.

Aims

This project will explore some novel approaches to the problem through a combination of high-quality data from the new generation telescopes and developing a new framework for the analysis and interpretation. A particular focus will be on the exploration of a multitude of phase and amplitude modulation phenomena in pulsar radio emission; e.g. "swooshing" (episodic emission at earlier phases), "sub-pulse drifting" (progressive phase shifts in emission structure with pulsar rotation), "nulling" (apparent cessation of emission), "moding" (sudden changes to the state of emission), etc. The wealth of new observational data emerging from facilities such as the Murchison Widefield Array (MWA) and telescopes that share common skies (e.g. the Giant Metrewave Radio Telescope and the Parkes Murriyang telescope) open up new avenues, in particular the investigation of the frequency dependence of these phenomena. The study will focus on in-depth studies of individual objects, as well as a growing sample of pulsar detections across a large frequency range (~80 MHz to 4 GHz) to investigate the prevalence of relativistic (i.e. retardation/aberration) effects. The project will explore ideas that can now be tested or scrutinised for further theoretical exploration.

Objectives

1) In-depth investigation of various phase and amplitude modulation phenomena on targets of special interest; e.g. pulsars that exhibit multiple such phenomena. 

2) Investigate the frequency dependencies of pulsar radio emission and phase modulation phenomena, by taking advantage of a growing body of low-frequency detections (e.g. from the SMART survey under way with the MWA) and similar large data sets emerging from other facilities. 

3) Further develop the framework for analysis, interpretation, and the exploration of new theoretical ideas;  e.g. signatures of retardation/aberration effects in the pulsar profiles and the inference of emission heights.

Significance 

Aside from the excitement of venturing into one of the long-standing problems in astrophysics,  there is renewed interest in this challenging topic, which largely stems  from recent advancements in the field of fast radio bursts (FRBs) and long period transients whose emissions seemingly share parallels to those of pulsars, as well as from the substantial progress being made with international pulsar timing array projects, where ultimately the intricacies of pulsar emission processes will dictate the precision attainable with pulsars as clocks. Pulsar astronomy is a headline science for the SKA, and thus the project is directly aligned with the goals of SKA science.

This research will be conducted at the Curtin Institute of Radio Astronomy (CIRA), the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), a joint venture with the University of Western Australia supported by the Western Australian State government. The successful candidate will work in a vibrant research environment interacting with staff and students across the Curtin node of ICRAR that hosts a strong group specialising  in astronomical science, engineering and high-performance computing. The project will leverage a large body of high-time-resolution data collected using the MWA and new observations using the MWA as well as data from other major facilities such as the Giant Metrewave Radio Telescope (GMRT) and the Parkes Murriyang 64-m telescope in New South Wales. Data processing will make use of supercomputing resources available at the Pawsey Supercomputing Centre (Perth) and Swinburne University’s OzSTAR supercomputer. Pulsar astronomy being a headline science theme for the international Square Kilometre Array (SKA) project, of which the MWA is a Precursor, the project is extremely well aligned with the key science goals of the SKA, and it will both inform and steer developments of pulsar science planned with the SKA.

• Future Students

• Faculty of Science & Engineering
  • Science courses
  • Engineering courses

• Higher Degree by Research

• Australian Citizen
• Australian Permanent Resident
• New Zealand Citizen
• Permanent Humanitarian Visa

• Merit Based

The annual scholarship package, covering both stipend and tuition fees, amounts to approximately $70,000 per year.

In 2024, the RTP stipend scholarship offers $35,000 per annum for a duration of up to three years. Exceptional progress and adherence to timelines may qualify students for a six-month completion scholarship.

Selection for these scholarships involves a competitive process, with shortlisted applicants notified of outcomes by November 2024.

1

All applicable HDR courses.

This project is ideal for a candidate with a sound background in physics and astrophysics, and a strong aptitude for exploring novel ideas for relevant observational analysis and interpretations, and for developing the theoretical framework. A background in radio astronomy with research experience is an additional advantage.

 

Please send your CV, academic transcripts and brief rationale why you want to join this research project via the HDR expression of interest form to the project lead researcher, listed below. 

You must be enrolled in a Higher Degree by Research Course at Curtin University by March 2025.

Project Lead: Dr Ramesh Bhat