Lab Canada

Supercomputer helps telescope see echos from the big bang

Toronto, ON – An international collaboration of scientists has announced the first results of the ACT project, probing the early years of the universe. The announcement was made last week at the High Performance Computing Symposium (HPCS2010) by Jonathan Sievers, of the Canadian Institute for Theoretical Astrophysics.

The Atacama Cosmology Telescope is one of the largest telescopes of its kind, and the flood of data from this instrument in Chile in one day is the equivalent of a decade of data from an earlier satellite experiment. This requires the largest computers to make sense of it all — including SciNet’s GPC, the largest computer in Canada.

“SciNet is essential for the Atacama Cosmology Telescope (ACT) project. The computer has enabled a new frontier in producing maps of the early universe, and is changing the way cosmologists make sense of the cosmos,” said Professor Lyman Page of Princeton.

The first results have already given cosmologists the first glimpse of the transition from a simple universe to one containing the more complicated structures seen in the presentation. As part of the investigation, the team has identified previously unknown clusters of galaxies and is following them up with optical observations to determine their distances and masses.

“In other words, we have begun to observe how the largest objects in the universe, the clusters of galaxies, emerged from the primordial plasma,” said Dr Sievers, at HPCS2010.

Three miles above sea level, on a mountain in Chile, the Atacama cosmology telescope uses cameras cooled to near absolute zero to observe radiation from the earliest visible stages of the universe. The ACT project goals are to study how the universe began, what it is made of, and how it evolved to its current state. ACT makes detailed maps of the cosmic microwave background (CMB), a relic radiation left over from the Big Bang. The signal is extremely faint, so months of continuous data-taking is necessary. Turning this data into a map of the sky requires the inversion of a 10 trillion by 10 trillion element matrix, an enormous computational task. Complicating matters is that at these fine scales, clusters of galaxies emerge from the primordial plasma and leave their imprint on the CMB – a treasure trove for astrophysicists, but a signal that must be disentangled from the rest. Without large computers like SciNet’s GPC, ACT’s science would not be possible.