First estimates of ionised Helium clumping factors

Estimating the Intergalactic Medium (IGM) ionisation level of a region needs proper treatment of the reionisation process for a large representative volume of the Universe. The clumping factor, a parameter which accounts for the effect of recombinations in unresolved,...

Old, gas-rich galaxies likely had early star formation boom

The most massive stars (with masses up to a hundred times the mass of our sun) explode as supernovae at the end of their life and release huge amounts of energy and material into their neighbourhoods. These phenomena are so energetic that they can alter the rate of...

Where are all the pulsars at the Galactic Centre?

As stable, regularly pulsing rotators, pulsars are superb instruments for testing theories of gravity. An important test of General Relativity is the behaviour of bodies in extremely strong gravitational fields. The detection of a pulsar in the gravitational field of...

HMFcalc: An online tool for calculating halo mass functions

The halo mass function describes the abundance of collapsed dark matter objects of a given mass and can be used in observational tests to constrain cosmological parameters and in theoretical models to predict galaxy clustering and even basic galaxy properties. As one...

On the origins of Fast Radio Bursts and perytons: a statement

Earlier this year, we issued a press release for the publication by our PhD student Emily Petroff at Swinburne University and her supervisors and colleagues, reporting the first real-time observation of a Fast Radio Burst (FRB). This paper added to a growing body of...