CIFAR launches the program in Cosmology under the direction of
The program is reviewed by an international panel of experts
CIFAR Senior Fellow Hugh Couchman (McMaster University) releases the first
CIFAR Associate Fellow Glenn Starkman (Case Western Reserve University) and
The BOOMERanG team publishes findings from its 1998 flight, which
CIFAR Senior Fellow Barth Netterfield (University of Toronto) overseas another
An international partnership between four organizations commits to building the
CIFAR researchers continue work on the reconfiguration of the Cosmic
CIFAR Fellow Andrew Cumming (McGill University) makes two important discoveries
CIFAR Fellow Frans Pretorius (Princeton University) makes significant progress in
CIFAR fellows Ludovic Van Waerbeke (University of British Columbia) and
CIFAR Senior Fellow Hugh Couchman (McMaster University) and his team
Calculations by CIFAR Senior Fellow Matthew Choptuik (University of British
CIFAR Fellows Ludovic Van Waerbeke (University of British Columbia) and
Fellow Ue-Li Pen (CITA/Toronto) and collaborators at Carnegie Mellon University
Fellow Luis Lehner (University of Guelph) and Fellow Frans Pretorius
Using the new Atacama Large Millimeter/submillimeter Array (ALMA) telescope, the
The Planck Space Telescope collaboration publishes results, providing researchers with
Canada begins construction on the Canadian Hydrogen Intensity Mapping Experiment
CIFAR fellows Ingrid Stairs (University of British Columbia), Victoria Kaspi
The Thirty Meter Telescope project receives $25 million in Canadian
CIFAR launches the program in Cosmology under the direction of William Unruh (University of British Columbia). The program seeks to understand how the structure in the Universe we observe around us arose and developed in time. To do this, they aim to develop the quantum theory of gravity and other fields, essential ingredients to the generation and evolution of space-time, and use it to make predictions about the earliest micro-moments of the Big Bang. In addition, they intend to develop experiments and make observations to test these predictions. Fundamental questions that drive this research include how old the Universe is and how much mass it contains. The work has insights from new developments in such areas as pure and applied mathematics, statistics, computer science and philosophy, as well as physics and astronomy.
The Science Council of British Columbia awards Program Director William Unruh (University of British Columbia) the B.C. Science and Engineering Gold Medal in natural sciences. Unruh is lauded for his application of quantum field theory to black holes and for the Unruh effect, which states that the temperature of a moving thermometer in a vacuum is not zero.
CIFAR Senior Fellow Werner Israel (University of Victoria) finds that the warping of space-time near a black hole singularity does not necessarily vibrate wildly, catching all objects nearby and destroying them. He and his team finds that the warping may instead grow smoothly and continuously in a manner that is “null,” so that light signals can skim along the edge of the singularity and not be caught. The work leads to follow-up research by others that suggest the singularity inside a black hole may be chaotic when the hole is young, but evolve quickly into the smooth variety as the hole ages.
World-renowned physicist Stephen Hawking joins CIFAR as an associate fellow in the Cosmology & Gravity program. He presents a CIFAR sponsored lecture at the University of Alberta on the future of the Universe, taking the stage with CIFAR fellows Werner Israel and Don Page. Hawking visits Edmonton on his way to participate in an international conference in honour of Israel, who is his close collaborator.
At the annual CIFAR Cosmology & Gravity program meeting, CIFAR associate fellows Lev Kofman (Canadian Institute for Theoretical Astrophysics) and Andrei Linde (Stanford University) present their classic paper “Reheating After Inflation” for the first time. It remains one of the top-cited works in the field today, providing a new understanding of events in the earliest moments of the Universe.
The program is reviewed by an international panel of experts and renewed for the second time. It is deemed to have transformed cosmology research in Canada over the decade since its launch. During that period, the program focused on two related but distinct specialties: physical cosmology — the application of the laws of physics to study the origin and evolution of the Universe; and quantum gravity — the effort to marry Einstein's theory of general relativity with quantum mechanics. Canada ranks third in the world in theoretical cosmology, after the United States and the U.K., and the reviewers write that this is due in large part to the support and encouragement of CIFAR.
CIFAR Senior Fellow Hugh Couchman (McMaster University) releases the first version of his cosmological simulation code called Hydra. Hydra helps scientists develop realistic numerical models of the formation of cosmic structures, such as galaxies and the first generation of stars. It becomes widely used worldwide.
Scott Tremaine (Princeton University) succeeds William Unruh as director of the program. Tremaine is regarded as one of the world’s best theoretical astrophysicists. Under his direction, the program’s name changes to Cosmology & Gravity, to better reflect the diversity of its research, and the fellows embark upon an ambitious plan to expand and diversify the program’s approach to understanding the cosmos.
Program Director Scott Tremaine (Princeton University) finds that a recently discovered planet around a star called 16 Cyg B has a highly irregular orbit pattern, and presents a theory to explain why. Tremaine and his colleagues suggest that the star’s companion star, 16 Cyg A, is exerting a constant gravitational pull that is changing the planet’s orbit. They posit that planets orbiting within two-star systems may sometimes collide with the primary star.
CIFAR Senior Fellow Valeri Frolov (University of Alberta) and Igor Novikov publish the book Black Hole Physics, summing up the evidence from decades of theoretical research on the possibility that there are black holes — objects with a gravitational pull so strong that nothing, even light, can escape. Studying the physics of black holes has improved our understanding of much more than outer-space. It has tested our theories of space, time and gravitation.
CIFAR Associate Fellow Glenn Starkman (Case Western Reserve University) and collaborators find evidence contradicting previous assumptions that the Universe is infinite if it has a negative curvature. They find the Universe could be finite and small, in relative terms, even if its curvature is negative, and we could measure how big it really is. Understanding the Universe’s shape and size could help scientists work out how it was born and what happens in the moments afterward. If the Universe is smaller than the sphere of last scattering (where the cosmic microwave background originates), these intersections should be visible as circles of identical microwave background fluctuation on the sky.
The Balloon Observations Of Millimetric Extragalactic Radiation and Geophysics launches its first Antarctic flight, circling the South Pole for two weeks as it scans the sky to measure temperature fluctuations in the cosmic microwave background. CIFAR fellows J. Richard Bond (University of Toronto) and Barth Netterfield (University of Toronto) are involved in the project. The results of this flight, published in 2000, change our understanding of the Universe’s structure.
Associate Fellow Robert Myers discovers a remarkable effect — the dielectric or "Myers" effect of D-branes. D-branes are extended objects that play a central role in our modern understanding of superstrings in string theory, which holds that the Universe is made of one-dimensional, vibrating strings at its smallest scale. Myers’ theoretical breakthrough is that D-branes swell in higher dimensions in the presence of applied fields.
The BOOMERanG team publishes findings from its 1998 flight, which indicate that the Universe is cosmologically flat. This finding is an important confirmation for the theory of inflation, which suggests the Universe underwent a period of exponential expansion in the moments after the Big Bang. Boomerang also indicates that the energy density of the Universe is dominated by Einstein’s cosmological constant, and that its mass is dominated by dark matter of some unknown form.
CIFAR Fellow Don Page (University of Alberta) examines the puzzle of what would happen if a box of radiation were lowered very near the horizon of a zero-temperature (extreme) black hole. In theory, the black hole should allow all but an extremely small fraction of the box energy to be extracted. Then if the box were dropped in to the black hole with infinitesimal energy, it should increase the black-hole entropy — a measure of disorder — only very slightly, and yet the finite entropy of the radiation in the box should be lost. This seems to cause trouble for the second law of thermodynamics, which states that any cyclical process will lead the entropy to increase or remain the same. Page shows theoretically how to save the second law in this novel thought experiment.
CIFAR Program Director J. Richard Bond (University of Toronto) investigates constraints on the size of compact hyperbolic models of the Universe (those with negative curvature but finite volume) using observations of large-angle fluctuations in the cosmic microwave background radiation. He finds that the overall scale of the topology of the Universe must be about the size of the domain of last scattering of the CMB photons, otherwise the patterns in the CMB are incompatible with the observations.
CIFAR Fellow Mark Chen is part of the Sudbury Neutrino Observatory (SNO) team, led by Advisor Arthur B. McDonald (Queen’s University), that solves a 30-year mystery about the properties of neutrinos, the billions of elementary particles of matter emitted by the nuclear reactions that fuel the sun. Particle properties are known to have deeply influenced the evolution of the Universe from its earliest moments into the present. Since the 1970’s, several experiments had detected neutrinos arriving on Earth, but had found only a fraction of the number expected according to detailed theories of energy production in the sun. The SNO team discovers that one type of neutrino that had seemed to be missing actually transforms into other neutrino types on the journey between the sun and the Earth. This discovery also indicates that neutrinos have mass, and will be very important in reaching a greater understanding of the Universe at the most microscopic level. In 2015, Arthur McDonald wins the Nobel Prize in Physics for this discovery.
Program Director J. Richard Bond (University of Toronto), whose research interests are very broad, leads the assembly of a team for the theoretical analysis of fluctuations in the cosmic microwave background radiation, data that have major implications for the geometry of the Universe, for its contents of ordinary matter, dark matter, and dark energy, and for its ultimate fate.
Scientists estimate the Universe’s mass by studying the pattern of how hundreds of thousands galaxies cluster together. CIFAR associate fellows John Peacock (University of Edinburgh), George Efstathiou (University of Cambridge) and Richard Ellis (California Institute of Technology) are collaborators on the project, which confirms the standard model of cosmology — a flat, low-density Universe.
New data is unveiled from the international Cosmic Background Imager (CBI), located high in the mountains of Chile. The CBI is a highly sensitive 13-antenna device that makes images of the cosmic microwave background radiation. The new data provides a significant improvement in the angular precision of the primordial structures that grew about 14 billion years ago into the massive galaxies we see today and detects wavelengths that reveal radiation hot spots correlating to “clumps” of matter in an otherwise smooth Universe. These “clumps” eventually became clusters of galaxies. The data also provides insights into other major constituents of the Universe, including ordinary matter, dark matter and dark energy. CIFAR fellows J. Richard Bond, Ue-Li Pen and Barth Netterfield (all University of Toronto) are collaborators on the project.
CIFAR Senior Fellow Barth Netterfield (University of Toronto) overseas another flight by the balloon-borne telescope BOOMERanG, which circles the South Pole for 13 days, scanning about 2,000 square degrees of the cosmic microwave background.
An international partnership between four organizations commits to building the Thirty Metre Telescope on Mona Kea, Hawaii. The telescope is projected to be the most powerful optical telescope ever made. The four groups — the Association of Canadian Universities for Research in Astronomy, the California Institute of Technology, the University of California, and the (US) Association of Universities for Research in Astronomy, receive $10 million in funding from the Canada Foundation for Innovation. CIFAR Senior Fellow Raymond Carlberg (University of Toronto) is the project’s Canadian lead. For more information, please see the University of Toronto’s 2006 story about the project.
CIFAR Senior Fellow Matthew Choptuik (University of British Columbia) and collaborators complete an intense 18-month research project on unstable black strings. Black strings, like other models currently considered by theoretical physicists, exist in a Universe with greater than three spatial dimensions. The group directly simulates the dynamical behaviour of the black string, using large scale computer resources. The research provides intriguing hints of what the end state could possibly be like. Choptuik notes that CIFAR researchers William Unruh (University of British Columbia), Robert Wald (University of Chicago) and Advisor Gary Horowitz (University of California, Santa Barbara) played important roles in encouraging his team to take on the challenge of performing the difficult simulations required to shed light on this fascinating problem.
CIFAR researchers continue work on the reconfiguration of the Cosmic Background Imager (CBI) experiment in Chile, collecting new data since September 2002. Program Director J. Richard Bond (University of Toronto) and others provide new research insights and analyze stage of these experiments to determine whether the data agrees with theoretical predictions.
CIFAR Fellow Andrew Cumming (McGill University) makes two important discoveries related to neutron stars in binary star systems, meaning two stars that orbit each other. When stars orbit each other, gravity produces a tidal effect on the stars’ gases, much like the ocean tides produced by the Moon’s orbit around the Earth. When a neutron star is paired in a binary system with a regular star, the tides on the regular star are so large that hydrogen and helium gases are stripped away and fall from the star onto the surface of the neutron star. There they are compressed and heated in the strong gravity for about a day before undergoing a spectacular thermonuclear runaway: thermonuclear reactions rapidly burn the gases into heavy elements, giving a bright burst of X-rays lasting tens of seconds. Detected by orbiting X-ray observatories, these bursts provide a brief but repeating glimpse of a neutron star’s surface. Cumming finds that the long X-ray bursts can be explained only if the neutrino emission is quite inefficient. He discovers a new way to probe the properties of matter compressed to densities much greater than anything on Earth.
CIFAR Fellow Andrew Cumming (McGill University) shows that the predicted winds on neutron stars are unstable, spontaneously breaking up into a pattern of bright hot and cold spots. The discovery provides an explanation for high frequency oscillations that had been detected in X-rays from neutron stars. These burning processes also happen in other situations in astronomy, but can be studied on short timescales because of the extreme physical conditions that exist on the surface of neutron stars.
CIFAR Fellow Frans Pretorius (Princeton University) produces the first successful numerical simulations of two black holes orbiting and finally merging with each other. Using new and original solution methods he is able to achieve a result that had eluded scientists for 40 years. Pretorius’s simulation makes it possible for scientists to predict the nature of gravitational waves emitted in black hole mergers and to help identify them. Once detected, these waves are expected to reveal information about the merged black holes they came from and potentially lead to major new insights into the workings of the Universe.
CIFAR Fellow Frans Pretorius (Princeton University) makes significant progress in understanding how the strong gravitational fields around black holes warp space-time. His novel method predicts the velocity of a new black hole created by two black holes merging together. He predicts this velocity is caused gravitational waves pushing on the original black holes as they merge. He finds that velocities of 4000 km/s are possible, about 40 times more than thought possible in the past. He also explains why such great velocities are realistic — they are derived from the reserve of space-time energy the merging black holes carry around with them.
CIFAR fellows Ludovic Van Waerbeke (University of British Columbia) and Henk Hoekstra (Leiden University) collaborate in a large, international project to obtain the most precise measurements of the distortion of light from distant galaxies due to the gravitational pull of intervening massive structures in the Universe. They use the largest ground-based surveys available to date (including the Canada-France-Hawaii Telescope Legacy Survey). The data allows them to measure the density of dark matter. For the first time, they are able to show results on the amount and distribution of dark matter in the Universe that is consistent with other observational probes.
The BLAST balloon-borne telescope launches from Antarctica. Scientists including Senior Fellow Barth Netterfield (University of Toronto) launch the highly sensitive bolometer and fly above the atmosphere to image radiation at sub-millimetre wavelengths, which cannot be detected as readily from the ground. In addition to leading the data analysis, Netterfield and other Canadian scientists build much of BLAST’s structure and instrumentation. Its first results are published in 2009.
CIFAR Senior Fellow Raymond Carlberg (University of Toronto) leads an international team of researchers working on the Canada-France-Hawaii Telescope Legacy Survey supernova program. The survey aims to distinguish between several competing theories to define the mysterious dark energy that is causing the expansion of the Universe to accelerate. Measuring the distances to observed supernova explosions becomes one of the main tools of choice for characterizing the effects and parameters of dark energy because it provides a reliable indicator of the Universe’s rate of expansion. Carlberg’s team devises a technique to discover the most distant supernovae ever seen, estimated to have occurred approximately 10 billion years ago. The technique involves adding together six months of images to create a very deep image of the sky. This allows the researchers to look for objects that changed in brightness over a long period of time. The survey results favour Einstein’s theory about the nature of the accelerating Universe, which has a parameter controlling this expansion known as the cosmological constant. The team reduces the statistical uncertainty on this parameter to only 4.4 per cent.
CIFAR Senior Fellow Hugh Couchman (McMaster University) and his team use state-of-the-art supercomputer simulations to model the formation of a small galaxy. The high-resolution simulations enable Couchman’s group to accurately model the very violent processes that galaxies suffer at their births. Dense gas clouds in the galaxy form massive stars, which, at the ends of their brief lives, blow up as supernovae. These huge explosions push the interstellar gas clouds back and forth in the centre of the galaxy. The group’s model shows that this “sloshing” effect — similar to water in a bathtub — kicks most of the dark matter out of the centre of the galaxy. This violent early history neatly solves the discrepancy between theory and observation of small galaxy formation, and exposes a critical relationship between gas and dark matter that was previously largely ignored.
Calculations by CIFAR Senior Fellow Matthew Choptuik (University of British Columbia) and his team provide evidence against the theory that two particles colliding head-on at extremely high speeds, such as the collisions at the Large Hadron Collider, could create a tiny black hole. In fact, they suggest that particles might instead become relatively transparent to each other, so that they would effectively pass through one another during high energy collisions, emerging with their original identities largely intact. Choptuik collaborates with CIFAR Fellow Frans Pretorius (Princeton University) to extend and refine these calculations, previously limited to impact velocities significantly less than those that are encountered in the LHC.
M. W Choptuik and F. Pretorius, “Black hole production at LHC?” MPI-AEI, Golm, Germany, MPI-AEI Colloquium (April 30, 2008).
R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University) and colleagues confirm an important prediction of Einstein’s general theory of relativity using the now-famous “double pulsar” system. Pulsars are rotating neutron stars that emit beams of radio waves. The rotation creates a “lighthouse effect,” causing the source to appear to pulsate. The double pulsar system, discovered in 2003, is the first observed instance of two pulsars orbiting each other. Its brief orbit time of 2.4 hours, combined with its inherent pulsar properties, makes the double pulsar a particularly important test of relativity in a regime where it is a strong effect. Einstein’s theory predicts that the spin axis of at least one of the pulsars should precess (like a wobbling top) with time. Kaspi and her team makes the first quantitative measurement of this effect, showing that it agrees with Einstein’s theoretical prediction.
R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University) and her PhD student, Anne Archibald, discovers a “cosmic act of recycling.” They observe a dying pulsar that has very recently been brought “back to life” by drawing in material from a neighbouring star, thus increasing its own rotation speed. This transfer of material was first seen by an independent research group in 2000; however, they were not able to detect the pulsar, owing to the then in-falling material quenching the pulsar’s radiation. They find that nine years later, the pulsar is now “on” and spinning fast. Without such recycling, pulsars normally slow down as they age, and eventually disappear. But this lucky pulsar, though very old, was very much alive — extremely bright and spinning rapidly. Researchers had previously theorized that such recycling must take place, but no one had seen the process in progress.
The Planck telescope is launched in 2009 to detect the Cosmic Microwave Background (CMB) – the cooled remnant of the first light of the Universe. The Planck mission involves Program Director J. Richard Bond and Senior Fellow Barth Netterfield (both University of Toronto), Associate George Efstathiou (University of Cambridge), and Advisor Simon White (Max Planck Institute for Astrophysics). The European Space Agency’s Planck project is at: http://www.cosmos.esa.int/web/planck
The BLAST balloon-borne telescope releases results from its Dec. 2006 flight. The telescope’s data includes the first-ever images of sub-millimetre radiation emitted from the clouds of gas and dust within which stars are formed. The dust absorbs starlight, hiding many young stars from view to the human eye. By imaging this dust in galaxies out to a distance of over 10 billion light years, the researchers are able to determine the location of the half of the starlight in the Universe that is obscured by dust. They plot out the history of star formation in the Universe over that critical very early period. The team also maps star formation in our own Milky Way galaxy in unprecedented detail over a wide range of evolutionary states.
CIFAR Fellows Ludovic Van Waerbeke (University of British Columbia) and Henk Hoekstra (Leiden University) contribute to an international study that confirms that the rate of expansion of the Universe is accelerating, just as predicted by Einstein’s theory of general relativity. Cosmologists first observed this acceleration about a dozen years ago and worked towards understanding its source. Only about 5 per cent of the Universe is made up of “normal” matter as we know it and approximately 20 per cent is so-called “dark matter.” The international team’s findings result from an intensive study of over 446,000 galaxies detected in the largest-ever survey conducted by the Hubble Space Telescope, called COSMOS. Their study makes use of a technique called “weak gravitational lensing” pioneered by Van Waerbeke more than a decade ago. It allows researchers to infer the location of dark matter by observing how light travelling toward Earth from distant galaxies is distorted by the dark matter’s gravitational pull. The team is able to reconstruct a three-dimensional map of the dark matter in the study area and observe precisely how it evolved through the Universe’s history. The findings show for the first time that gravitational lensing is sensitive to the accelerated expansion of the Universe, independently from any other cosmological probe.
Fellow Ue-Li Pen (CITA/Toronto) and collaborators at Carnegie Mellon University and the Academia Sinica in Taiwan make pioneering observations using a new tool they developed for mapping large cosmic structures. Their technique, known as “intensity mapping,” holds the potential to shed light on the mysterious nature of dark energy. It maps and measures the radio frequency radiation emitted by hydrogen, the most plentiful element in the Universe. Their efforts lead to a new collaboration to map a large fraction of the Universe, called the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, which involves researchers from across Canada, including Cosmology and Gravity Program Director and Fellow J. Richard Bond (CITA/Toronto) and Fellow Matt Dobbs (McGill).
Fellow Luis Lehner (University of Guelph) and Fellow Frans Pretorius (Princeton University) develop a new supercomputer simulation that increases our understanding behaviour of how unstable black holes in higher dimensions behave. Lehner and Pretorius’ simulation show that a class of cylindrical black holes in higher dimensions cascaded into an infinite sequence of increasingly smaller spherical black holes connected by ever-thinning cylindrical black holes. The researchers calculate that this pattern eventually led to the development of a naked singularity when the cylindrical segments reach zero radius. A singularity is a “point” at the core of a black hole, where gravity becomes infinitely strong. The significance of the researchers’ finding was in violation of the “cosmic censorship conjecture,” which asserted that naked singularities should never form. This hypothesis fits within understandings of space-time proposed by the general theory of relativity — our modern theory of gravity. Yet, in extreme regimes like those around a singularity, this theory conflicts with the physics described by quantum mechanics. Thus, a naked singularity can expose a deep inconsistency in our understanding of the world.
An international team of researchers, including R. Howard Webster Foundation Fellow Victoria Kaspi and Global Scholar Slavko Bogdanov (both McGill University), facilitates the first discovery of a new pulsar through a global volunteer computing initiative. Kaspi leads a group conducting a large-scale survey of pulsars in the Milky Way galaxy using the world’s largest radio telescope at the Arecibo Observatory in Puerto Rico. Pulsars are rather precise clocks and can be used to detect gravitational waves, a yet-to-be observed prediction of Einstein’s general theory of relativity. As more pulsars are discovered and monitored, the chance of detecting gravitational waves increases. Discerning pulsar signals from other radio waves picked up by the Arecibo telescope involved running complex algorithms that require significant computing resources. Kaspi’s group partners with the Einstein@Home initiative, which uses donated time from the home and office computers of 250,000 volunteers from 192 countries. The first detection of a pulsar through this program highlights the power of this form of computing and the potential of this survey for future discoveries.
The European Space Agency’s Planck Telescope releases its first data findings, including the discovery of 30 galaxy clusters and the detection of 15,000 sources of microwaves. Planck also discovers that a microwave fog covering our galaxy, the Milky Way, comes from fast-spinning dust grains in space.
The South Pole Telescope finds direct evidence that the Universe’s first light, or cosmic microwave background, is lensed, or bent, by dark matter and galaxies. The Atacama Cosmology Telescope also confirms the lensing, which is consistent with the theory of the cosmic web. This information can be used to constrain the Universe’s curvature and the nature of the dark energy. Global Scholar Keith Vanderlinde (University of Toronto) and Senior Fellows Matt Dobbs and Gilbert Holder (both McGill University) are collaborators on the South Pole Telescope.
Fellows Julio Navarro (University of Victoria), Hugh Couchman (McMaster University), Associate Fellow Carlos Frenk (University of Durham) and Advisor Simon White (Max Planck Institute for Astrophysics) take part in the “Aquila Project,” a comparison of state-of-the-art simulations of galaxy formation by 13 research groups around the world. Each group works with the same initial conditions for galaxy development, and they compare the findings of each group’s model, based on parameters such as star formation rates and galaxy size. The results provide valuable insights on how to improve the models such that they create and evolve galaxies that better match what we see in nature. The project reveals a considerable improvement in the degree to which scientists can simulate many gross properties of galaxies, owing to an increasing sophistication of numerical algorithms in the previous decade.
C. Scannapieco et al., “The Aquila comparison project the effects of feedback and numerical methods on simulations of galaxy formation,” Monthly Notices of the Royal Astronomical Society 423, 2 (2012): 1726-1749 doi: 10.1111/j.1365-2966.2012.20993.x.
Using a camera on the Canada-France-Hawaii Telescope (CFHT), an international research team co-led by CIFAR Fellow Ludovic Van Waerbeke (University of British Columbia) culminates five years imaging 10 million galaxies located about six billion light years away. As light emitted by these galaxies travels to Earth, it becomes distorted or bent by the gravitational force of massive objects — such as clumps of dark matter — that it passes on the way. By analyzing the distortions in the CFHT images of these far-away galaxies, the researchers are able to infer the distribution of intervening dark matter. Their results showed that dark matter is spread like a web through the Universe — concentrated in large clumps and strands, with vast spaces in between. The clumps of dark matter coincide with clusters of galaxies, as predicted. The team’s findings bring us closer to understanding the nature of dark matter and its role in the Universe.
Using the new Atacama Large Millimeter/submillimeter Array (ALMA) telescope, the largest ground-based astronomical project in the world, an international research team measures the distance of several early galaxies. By measuring how far these galaxies are from Earth, astronomers can determine how soon after the Big Bang the Universe started making new stars. The team, which includes Global Scholar Keith Vanderlinde (University of Toronto) and Senior Fellows Matt Dobbs and Gilbert Holder (both McGill University), discovers the galaxies using the South Pole Telescope, and then analyzes them more closely with the Atacama Large Millimeter/ submillimeter Array (ALMA). They find that some of the galaxies are farther away than previously thought. Several were forming stars when the Universe was less than two billion years old — a billion years earlier than expected — while two were even more distant, creating stars just one billion years after the Big Bang.
The Planck Space Telescope collaboration publishes results, providing researchers with the most precise view yet of the Universe soon after its birth. The telescope detects the Cosmic Microwave Background (CMB) — the cooled remnant of the first light of the Universe. This international collaboration reveals that our Universe is 13.82 billion years old — about 100 million years older than previously thought — and is expanding more slowly than previously determined by earlier, less-precise instruments. It also refines our understanding of the composition of the Universe, showing that it is made up of slightly more matter and slightly less dark energy than was measured by earlier experiments.
Canada begins construction on the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a stationary telescope that will construct images from incoming radio waves. CIFAR fellows have contributed significantly to the design of CHIME, including Senior Fellow Matt Dobbs (McGill University), Program Director J. Richard Bond (University of Toronto) and several others. In addition to mapping the Universe, CIFAR’s R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University), Senior Fellow Ingrid Stairs (University of British Columbia), and Associate Fellow Scott Ransom (National Radio Astronomy Observatory) collaborated with a team of CIFAR researchers to recognize that with only a small modification to the backend system, the telescope could simultaneously search for Fast Radio Bursts. Only a handful of these seemingly random bursts of radio waves of unknown origin have been detected, but the vast sky-scanning capacity of CHIME may help to discover many more, and more often.
CIFAR Senior Fellow Ludovic van Waerbeke (University of British Columbia) and CIFAR Associate Henk Hoekstra (Leiden University) use a technique called gravitational lensing to calculate the approximate mass of dark matter in regions of the universe where it is especially difficult to measure. Dark matter is invisible — it neither absorbs nor reflects light — therefore scientists must find it based on its effects on the matter we can see. The researchers, using data from the Canada France Telescope Lensing Survey, study how the light bends as it moves through the Universe to determine the mass of the dark matter through which it travels. They build maps of dark matter within super clusters of galaxies, voids in space and strings of matter between galaxies called bridges. In total, the maps cover 154 square degrees of area in the sky, almost 100 times larger than any previous dark matter map.
CIFAR fellows Ingrid Stairs (University of British Columbia), Victoria Kaspi (McGill University) and others discover a unique triple-star system, offering the best opportunity to test a key tenet of Einstein’s theory of General Relativity. The stars include a white dwarf orbiting a pulsar, which together are orbited by a more distant white dwarf. While all these objects are collapsed remnants of exploded stars, the pulsar is much denser and emits lighthouse-like radio-wave beams as it spins on its axis. By timing these pulses with ultra-high-precision, the team calculates the system’s geometry and the stars’ masses with unprecedented accuracy. For more information, please see the University of British Columbia's news release.
The Thirty Meter Telescope project receives $25 million in Canadian funding. CIFAR Senior Fellow Raymond Carlberg (University of Toronto) serves as the Canadian project director. The project plans to build the first of the next generation of ‘super-sized’ telescopes, using new technology to decrease costs and enhance performance to study planets around other stars, galaxies in their earliest moments of formation, the super-massive black holes at the centres of galaxies, and the physics of the expansion of the Universe.
A burst of radio waves that have no clear origin but seem to have travelled across galaxies before arriving at our planet is discovered at the Arecibo Observatory in Puerto Rico by collaborators including CIFAR R. Howard Webster Foundation Fellow Victoria Kaspi (McGill University), Global Scholar Alumnus Slavko Bogdanov (Columbia University) and Senior Fellow Ingrid Stairs (University of British Columbia). Only a handful of other fast radio bursts have been detected previously, all of them by the Parkes radio telescope in Australia, with the first one reported in 2007. This is the first time that a different telescope has detected these same signals, bolstering evidence that they are not the result of equipment errors, but could be real and cosmic in origin.
The European Space Agency’s Planck satellite makes the most precise measurements of the polarization of the first light in the Universe, known as the cosmic background radiation, to date. The results show that the Universe forged its first stars 140 million years later than once thought, about 420 million years after the Big Bang. The new birth date aligns better with the rest of the Universe’s 13.8 billion-year history, including the formation of the first galaxies. Overall, the evidence by the Planck collaboration fleshes out a portrait of the early Universe that confirms the standard model of cosmology with more precision than ever before, from the Big Bang to an extremely rapid period of expansion called inflation, then to a long, slow process of cooling, expansion and formation of celestial bodies.
CIFAR Associate Fellow Arthur B. McDonald (Queen’s University), wins the Nobel Prize in Physics for his discovery that neutrinos change identities, a finding that showed these subatomic particles have mass. He shares the prize with Takaaki Kajita in Japan. McDonald led a research group including CIFAR Senior Fellow Mark Chen at the Sudbury Neutrino Observatory (SNO) that was studying neutrinos formed through nuclear reactions in the Sun. As these tiny particles travelled to Earth, two thirds of them seemed to be disappearing. McDonald’s group discovered that SNO was capturing the neutrinos, but they had changed identities from one to another of three different types. In order to make this change, the neutrinos must have mass.