Experiments

On This Page: The Simons Observatory  •  The Atacama Cosmology Telescope  •  The Hydrogen Intensity and Real-Time Analysis eXperiment

The Simons Observatory [⯅ Top]

The Simons Observatory (SO) is a multi-telescope observatory under construction in the Atacama desert of northern Chile that will significantly improve the quality of cosmic microwave background (CMB) measurements. Initial observations will start in 2023 and full operations will commence in 2024.

SO will be a huge leap forward in terms of sensitivity for a wide-area, high resolution CMB experiment. Our key science goals include:

• Probing the physics of the early Universe to test theories about the Big Bang.
• Better constraining how the Universe is expanding.
• Contributing to our knowledge of how galaxies form.
• Measuring the total mass of neutrinos.

Members of the Hincks group are heavily involved in developing software that will allow us to record, view and process the large volumes of data that the telescopes will record. We are also looking forward to using its data not only for the exciting science goals listed above, but also for our research areas of tracing cosmic structure and exploring the variable millimetre sky.

The Atacama Cosmology Telescope [⯅ Top]

The Atacama Cosmology Telescope (ACT) was a six-metre observatory in the Atacama desert of northern Chile (at the same location as SO) that observed the cosmic microwave background from 2007 to 2022.

ACT has made significant contributions to cosmology. A few select highlights:

• We were the first group to detect the gravitational lensing of the CMB by intervening cosmic structure, to provide evidence for dark energy using only the CMB. We have continued to provide improved measurements, and our most recent results received significant media coverage.
• We made the first measurement of the motion of galaxy clusters relative to the expansion of the Universe via the kinematic Sunyaev-Zeldovich effect, which we have since improved and solidified.
• We have made some of the most precise and detailed maps of the CMB that have confirmed and tightened the precision of many of the fundamental parameters that characterise the Universe.
• We have detected thousands of clusters of galaxies (including a remarkably huge one) and done numerous follow-up studies of their properties. We also used them to measure how the Universe has been cooling as it expands.
• We have measured the microwave brightnesses of distant galaxies and determined some of their important statistical properties.
• We have started searching for transient sources, and have put constraints on the existence of ‘Planet 9’.

Although ACT stopped observing in 2022, we still have lots of data to analyse and will continue publishing results over the coming years.

The Hydrogen Intensity and Real-Time Analysis eXperiment [⯅ Top]

The Hydrogen Intensity and Real-Time Analysis eXperiment (HIRAX) will consist of a large array of about 1000, six metre radio dishes located in the Karoo of South Africa. By working all together, the dishes yield a huge collecting area that will give us the high sensitivity and sufficient angular resolution we need to detect the baryon acoustic oscillation signal and measure how fast the Universe is accelerating—a key piece of empirical science that will help us figure out what dark energy, the mysterious field that today makes up about 70% of the Universe, might actually be. The Karoo is an ideal location for HIRAX because there is very little man-made radio signal to interfere with our measurement. The project is led from the University of KwaZulu-Natal but is an international collaboration that includes myself and others at the University of Toronto.