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Over the past 13 billion years the dark matter and atoms have been forged by gravity into a variety of structures (galaxies, groups, filaments), comprised a variety of mass forms (dark matter halos, stars, gas, dust, super-massive black holes), and produced a significant amount of energy (predominantly starlight and active galactic nucleus [AGN] light). Within the Distant Universe group we are attempting to build the empirical record of how mass has transformed, how energy is produced and how structure has emerged  from a smooth distribution of atoms to the myriad of filaments, groups, and galaxies we see today.

To do this we use data from the worlds leading ground and space-based telescopes which include: eROSITA, GALEX, HST, VST, VISTA, WISE, HERSCHEL and very soon the Australian Square Kilometer Array Pathfinder located in Western Australia, the Euclid, JWST and Roman space telescopes and the upcoming LSST facility.

The team at UWA consists of more than eight researchers working on various aspects of this project including: group and filament finding, structural analysis (bulge-disc decomposition) of galaxies, measuring and modelling the energy outputs, quantifying the various mass components (gas, stars and dust), comparing to numerical and hydro-dynamical simulations, and preparing for the next generation spectroscopic campaigns: GAMA, DEVILS, and WAVES.

Prospective students are sought to join the project and potentially work on any aspect of this program. The student will be trained in observational cosmology, galaxy fundamentals, and rigorous statistical analysis of big data sets (a generic 21st century skill). The work will include the use of extensive databases, development of sophisticated software pipelines, advanced visualisation methods, and image analysis and prepare the student for a career in Astronomy or in the Big Data and information sectors.

The student will also be expected to participate in observing runs at remote telescope locations inside and outside of Australia, processing of space satellite imagery, and become part of the extended GAMA, DEVILS and WAVES teams which now includes over 100 researchers across 30 countries and 4 continents.

Particular projects includes:

  • Mapping the baryons in all forms (plasma, stars, dust and neutral gas) from recombination to the present day. In particular we’re looking to find the missing half of the baryons currently unaccounted for in the nearby Universe. A key focus will be using the recently launched eROSITA space telescope in combination with our galaxy group catalogues from GAMA, DEVILS and WAVES to measure and model the hot and warm gas associated with galaxy groups and believe to be the largest baryon-sink. However we are also looking to revise our understanding of the growth of stellar mass, dust, and super-massive black-holes using high-quality panchromatic data from the ultraviolet to the far-infrared. Finally we plan to use the Australian Square Kilometer Array Pathfinder in WA to measure the evolution of the neutral gas associated with galaxies, galaxy groups and filaments. The image shows the total observable Universe with the Cosmic microwave Background added as the outer shell and us located at the centre. The various coloured dots show the spectroscopic campaigns that we are leading from the University of Western Australia and which form the backbone in converting the 2D images from space telescopes into 3D datasets we can use for science.

This image shows the total observable Universe with the Cosmic microwave Background added as the outer shell and us located at the centre. The various coloured dots show the spectroscopic campaigns that we are leading from the University of Western Australia and which form the backbone in converting the 2D images from space telescopes into 3D datasets we can use for science. (movie).

  • Modelling the energy output of galaxies from the far-UV to the far-IR and comparison to extensive multi-wavelength data. Here we look to produce a model describing the complete energy output of the Universe since the Big Bang phase including star-formation, AGN activity (including x-ray and radio emission) and dust reprocessing. A key highlight will be working with the deepest image to be taken with the upcoming James Webb Space Telescope

This image shows our current measurements and modelling of the extragalactic background light (all energy integrated over all time) and the energy being generated by the Universe today (lower panel) and broken into spheroids, discs, AGN and obscured AGN. As well as improving the data and models we now wish to extend to shorter (UV & x-ray) and longer wavelengths (sub-mm & radio). (movie).

  • Measuring and modelling the evolution of the Dark Matter Halo Mass function over all time. This project makes use of our leading spectroscopic surveys which are designed to be highly complete and optimal for identifying galaxy pairs and galaxy groups. The velocity dispersion of the groups allow us to measure the underlying dark matter and hence by building galaxy group catalogues in different redshift slices we are able to build up an accurate picture of the evolution of the dark matter over the latter half of the age of the Universe. This project is ongoing in the form of the GAMA and DEVILS surveys and over the next five years we lead the main study of this kind which will be conducted on the newly constructed European Southern Observtory’s 4MOST facility in Chile.

This image shows a screen shot of the underlying dark matter distribution (black dots) and our ability to measure it using galaxy (green) and galaxy groups (red). Using the WAVES Deep survey we will map the dark matter within a 50 square degree region from redshift 0.8 to the present day (a timeline of roughly 8 billion years). (movie).

Other projects include the study of galaxy merger rates, group dynamics, filament finding, and testing Cold Dark Matter simulations. Previous students are either engaged in permanent positions in astronomy research around the world, working in sectors which support this research, or are working in industry applying their statistical analysis skills in diverse areas (from malaria research to cancer research, hedge-fund management, weather forecasting, and the civil service).

 

If you are interested in these projects or similar, get in touch via simon.driver@icrar.org