Astronomy has progressed incredibly in the centuries since Tycho Brahe, Galileo Galilei, and Nicolaus Copernicus, and the equipment required by the professional stargazer today far exceeds the capabilities of their primitive telescopes.
Luckily for space scholars at the University of Toronto, the Dunlap Institute for Astronomy & Astrophysics is at the forefront of astrophysical instrumentation development.
While it would take a textbook to explore all the dazzling devices devised in part or whole at U of T, what follows is a glimpse at the instumentation being worked on right now.
What is a telescope?
What many people call telescopes are rarely used for research nowadays. The technology used frequently by amateurs and enthusiasts in the familiar lens-and-mirror tubes are largely obsolete in academia.
Though there are exceptions, such telescopes are largely used by amateur astronomers and enthusiasts.
Information in nature travels in waves, and some of the most useful waves are found on the electromagnetic spectrum. We perceive waves in the middle of the spectrum as colours, while radio waves have longer wavelengths and gamma rays and X-rays have shorter wavelengths.
Detecting different kinds of waves with different kinds of telescopes provides different kinds of knowledge about the cosmos. For example, much like how Hollywood spies use infrared goggles to detect human heat, infrared telescopes can be used to detect the temperatures of celestial objects.
The Canadian Hydrogen Intensity Mapping Experiment
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a telescope that detects extraterrestrial radio waves. Located at the Dominion Radio Astrophysical Observatory in the southern mountains of British Columbia, CHIME is mapping half of the night sky out to a distance of billions of light years, the largest volume of space ever surveyed.
The ‘hydrogen’ part of the name refers to its search for traces of neutral hydrogen, measurement of which would do much to preciscely constrain exotic theories of dark energy.
Yet there have also been other uses for CHIME.
“We’ve picked up a few other science goals along the way, from monitoring pulsars to finding Fast Radio Bursts, which have really leveraged the power of this new telescope,” said Professor Keith Vanderlinde, a Dunlap faculty member collaborating on the project, in an email.
CHIME was first put into use in September 2017, but U of T’s contribution to the instrument’s development goes back further in time.
“U of T has been involved in CHIME from the beginning, helping to plan and design the project from the ground up,” added Vanderlinde.
“During construction, our team focused on the supercomputer backend that allows the CHIME to ‘see’ the sky, converting the incoming raw radio waves into meaningful image data — processing almost [1,000 gigabytes per second] of raw data down to something more manageable — and which sits at the nexus of the many projects, producing distinct streams of data for each of them. Now that things are mostly up and running, we’re neck-deep in the commissioning and analysis efforts, to make sure we understand what it is we’re measuring.”
Canadian Initiative for Radio Astronomy
Led by Dunlap Director Professor Bryan Gaensler, the Canadian Initiative for Radio Astronomy (CIRADA) is less an experiment in itself and more of a network of projects, looking to increase Canadian participation in three telescopes: CHIME, the Karl G. Jansky Very Large Array (VLA) in New Mexico, and the Australian Square Kilometre Array Pathfinder.
The objective of CIRADA is to give Canadian astrophysicists the tools necessary to convert the massive streams of raw data from the telescopes into easy-to-use catalogues and photographs so that scientists and members of the public can explore the data sets and contribute to discoveries.
Contributing to the VLA Sky Survey (VLASS), U of T is leading the charge with CIRADA by focusing on analyzing cosmic magnetism.
“The VLASS is allowing three types of experiments with radio waves: mapping the emission from black holes, looking for explosions, and studying cosmic magnetism,” explained Gaensler in an email to The Varsity.
“As part of CIRADA, the U of T team is taking the images coming out of VLASS, and converting them into maps of magnetism in space, a bit like the simple maps of magnetism you probably made in high school by sprinkling iron filings around a toy magnet.”
An example of a ‘classic’ telescope, the Dragonfly Telescope Array began with the simple idea of latching together a number of commercially available camera lenses.
The brainchild of Dunlap’s Professor Roberto Abraham, the array was originally commisioned in 2013 with three Canon 400-millimetre lenses, the same type used at events like the FIFA World Cup. Instead of viewing football, the array was placed side by side and pointed up at the night sky to look for galaxies.
Today, the array has grown to 48 lenses, each modified to remove unwanted light. It is the world’s largest array composed solely of refracting telescopes, in contrast to the more popular reflecting telescope.
While simpler in concept, Dragonfly is by no means less useful than its larger, more complex counterparts.
Its multiple lenses act as filters and are useful in detecting faint objects as the filters produce accurate images devoid of optical noise.
Earlier this year, the array discovered what appeared to be a galaxy devoid of dark matter, an element previously thought to be ubiquitous in all galaxies.
Gemini Infrared Multi-Object Spectrograph
Infrared astronomers are stargazers working at higher frequencies than radio, but still at lower frequencies than visible light.
The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is U of T’s largest current contribution to the field of infrared astronomy.
Led by Dunlap’s Professor Suresh Sivanandam, GIRMOS is a spectrograph that separates the input it detects into its component wavelengths and records said components.
“GIRMOS is a one-of-a-kind scientific instrument specially designed to study very distant galaxies that are billions of light years away,” said Sivanandam in an email to The Varsity. “These galaxies are so small in the sky that we need to use cutting-edge optical technology, called adaptive optics, to get high resolution images of these objects. With GIRMOS, we will be able to study in detail how these galaxies look like and how they form their stars. This will help us piece together how our own galaxy formed.”
The project is based on data received by the Gemini Observatory, which has two telescopes in Hawaii and Cerro Pachon, Chile.
Despite the geographic distance, the project is a testament to Canadian ingenuity.
“GIRMOS is truly a Canadian project that has institutions that span coast-to-coast,” said Sivanandam. “It takes advantage of the well of scientific and technical expertise that exists within Canada to make this instrument a reality. This project is a pathfinder for future scientific instruments on the Thirty Meter Telescope, Canada’s next big telescope.”
Closer to home, Sivanandam also noted that “U of T has provided scientific leadership in many projects that make use of the Gemini Observatory, which has ranged from imaging planets around other solar systems to studying some of the galaxies of the early universe.”
South Pole Telescope 3G
Amundsen-Scott South Pole Station is located atop the geographic south pole, the southernmost point on Earth. Its exotic locale guarantees some of the harshest conditions known to humanity, just short of outer space.
“From February to November each year, the South Pole is inaccessible due to the harsh weather. We have two scientists called ‘winter-overs’ that stay at the station during this period, and work hard to keep the telescope running in some of the most extreme weather on the planet,” said PhD student Matt Young in an email. “The sun disappears below the horizon for 6 months, leaving them in 24/7 darkness and temperatures around -60 degrees C.”
Originally built by the United States, the station is now home to an international collection of astrophysical instruments, including the aptly-named South Pole Telescope (SPT).
The SPT detects waves in a number of wavelengths ranging from microwaves to submillimeter waves. Since the telescope’s construction in 2006, a number of cameras have been used to record said detections. The newest of these cameras is the SPT-3G, a microwave camera, the detectors for which are tested and characterised right here at U of T.
Vanderlinde, former Dunlap Fellow Dr. Tyler Natoli, and Young have been U of T’s principal contributors to the SPT.
Young travelled to the south pole in the winter of 2017–2018 to aid with installing the SPT-3G and is excited about the potential information to be gleaned from the newest camera.
“[The SPT-3G] will allow us to observe the Cosmic Microwave Background, light emitted just after the Big Bang, in more detail than ever before. We currently have a detector here in Toronto that I’ll be taking down to the South Pole with me to install in the camera,” wrote Young.