Project Overview

This project will examine the radio properties of the most distant supermassive black holes (SMBH). Known as quasi-stellar objects (QSOs) these objects are extremely luminous across the electromagnetic spectrum due to accretion on to the SMBH. Some QSOs produce powerful relativistic jets which can be observed at radio wavelengths. The successful candidate will use state of the art Australian radio surveys as well as utilising bespoke follow-up with other radio telescopes. They will then model the radio and optical data to (a) develop a model connecting the accretion and jet, and (b) study the impact of the jet on the host galaxy and environment.

Aims

The aim of this project is to conduct a systematic survey of the radio properties of the most distant QSOs in early Universe in order to understand early evolution of the most massive supermassive black holes. With many new large area radio surveys from Murchison Widefield Array and the Australian SKA Pathfinder now available, photometric measurements across a wide range of frequencies can be obtained for this large sample. Radio data at other frequencies will also be obtained to aid modelling of the radio and optical modelling.

Objectives

The objectives of this project are:  
- determine the radio properties of known samples of bright QSOs powered by the most massive black holes, 
- use novel techniques to select new samples of distant QSOs missed from current surveys, 
- use the radio data to model the jet power and its age, use optical data to model the accretion disk,  
- compare and expand existing models of the dependence of jet-power and accretion on black hole mass, accretion rate and spin.

Significance 

Understanding how billion solar mass black holes can form so early in the Universe is a key question in astrophysics. Current models require extreme situations for these SMBHs to form so quickly. The presence of powerful radio emission implies very high black hole spin and jet efficiency and hence limits the extreme formation models. In order to constrain the effect relativistic jets have on the accretion and evolution of nascent SMBHs a statistically significant population must be created.

The project will be hosted at 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. As such the successful candidate will be in a vibrant research environment with over 200 staff and students across the two ICRAR nodes working on a wide range of science, engineering and high-performance computing in the fields of radio astronomy, statistics and data science. 

The successful candidate will join an active group working on high redshift AGN at CIRA who work with many international collaborators. Co-supervisor Dr Nithya Thyagarajan is just across the road from the CIRA allowing easy collaboration with him as well as the larger group of astronomers at CSIRO.  

On top of the standard University support for computing and travel, additional resources from ICRAR for these activities may be available if required. In particular, we typically send PhD students to the annual scientific meeting of the Astronomical Society of Australia to present their work, participate in training opportunities, and to network with their peers and more senior astronomers from around Australia. Furthermore, extra resources will be available if an industry internship is undertaken.

An internship may be available for this project.This project is co-supervised by Dr Nithya Thyagarajan at CSIRO and will include an opportunity for an industry internship of 60 days at CSIRO.

• 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.

We are looking for a self-motivated PhD candidate with excellent organisation, problem-solving and project management skills. Candidates with strong quantitative skills, including familiarity with python and radio astronomy are desired for this project. Must be eligible to enrol in PhD programs at Curtin.

 

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 Nick Seymour