Assistant Professor Position at University of Toronto (Deadline May 20, 2013)

Assistant Professor Position at University of Toronto
(Deadline: May 20, 2013)

The Department of Astronomy and Astrophysics (DAA) in the Faculty of Arts and Science at the University of Toronto invites applications for a one-year contractually limited term appointment at the rank of Assistant Professor, beginning September 1, 2013.

Primary responsibilities will be undergraduate teaching, mentorship, and supervision, although teaching at the graduate level is a possibility; and carrying out independent research. Qualifications include a PhD; commitment to quality undergraduate education and experience; demonstrated commitment to excellence in teaching; a productive independent research program and a record of research excellence. Potential applicants are invited to visit our web site at http://www.astro.utoronto.ca.

The University of Toronto (www.utoronto.ca) offers the opportunity to teach, conduct research, and live in one of the most diverse cities in the world. Salary will be commensurate with the candidate’s qualifications and academic accomplishments.

All application materials must be submitted on-line by clicking on the link below. Applicants should submit a curriculum vitae, teaching dossier including a statement of teaching philosophy, and a research plan. Please direct any additional enquiries about this position to Professor Howard Yee at chair@astro.utoronto.ca.

The UofT application system can accommodate up to five attachments (total 10 MB) per candidate profile; please combine attachments in a single PDF file. Submission guidelines can be found at: http://uoft.me/how-to-apply.

Applicants should also ask three referees to send letters via e-mail directly to the department to astrochair@astro.utoronto.ca by the closing date, May 20 2013.

For more information about the Department of Astronomy and Astrophysics, please visit http://www.astro.utoronto.ca

To apply Online please click: https://utoronto.taleo.net/careersection/10050/jobdetail.ftl?lang=en&job=1300463

e-News: April 2013

ITEMS OF INTEREST POSTED ON THE CASCA WEBPAGES IN APRIL 2013:

     
CALENDAR:

CONNECT TO CASCA:
 
To submit news items, announcements and job postings, click here
To contact the CASCA Board, click here
To submit comments to the Long Range Plan Implementation Committee (LRPIC), click here
To submit comments to the Ground Based Astronomy Committee (GAC), click here
To submit comments to the Joint Committee for Space Astronomy (JCSA), click here

Postdoctoral Position at the University of Alberta (Deadline May 1, 2013)

A postdoctoral position is now available with Dr. Erik Rosolowsky at the University of Alberta with an emphasis on star formation, the interstellar medium, or nearby galaxies. The successful applicant will develop collaborative projects within these broad domains, subject to applicant background and mutual research interests.

The two-year position offers a $47k annual salary and $5k/year in travel funding, along with health benefits, computing and publication support, and a relocation allowance. Start dates are negotiable. The position has a nominal start date of September 1, 2013, subject to negotiation.

All postdocs will be encouraged to pursue their ongoing research efforts, collaborate with members of the astrophysics group, and develop new projects. The U. of Alberta physics department also includes groups researching cosmology, gravity, plasma, space, and particle physics.

Applicants should send a CV, publication list, and statements of research interests (one page) and research experience (two pages) to Dr. Rosolowsky as PDF files (erik.rosolowsky@ubc.ca). Applicants should also arrange for three letters of reference to be sent electronically. Application review will begin on May 1, 2013.

The University of Alberta hires on the basis of merit. We are committed to the principle of equity in employment. We welcome diversity and encourage applications from all qualified women and men, including persons with disabilities, members of visible minorities, and Aboriginal persons.

See http://www.postdoc.ualberta.ca/ for details of health benefits. The university postdoc supplemental health plan is included in all offers.

Baby Stars May Grow Massive From Feeding Enabled Collectively By Older Stars

Stars ten times as massive as the Sun, or more, should not exist: as they grow, they tend to push away the gas they feed on, starving their own growth. Scientists have been struggling to figure out how some stars overcome this hurdle.

Now, a group of researchers led by two astronomers at the University of Toronto suggests that baby stars may grow to great mass if they happen to be born within a corral of older stars –with these surrounding stars favorably arranged to confine and thus feed gas to the younger ones in their midst. The astronomers have seen hints of this collective feeding, or technically “convergent constructive feedback,” in a giant cloud of gas and dust called Westerhout 3 (W3), located 6,500 light years from us. Their results are published in The Astrophysical Journal (ApJ, 766, 85), available online at http://stacks.iop.org/0004-637X/766/85.

“This observation may lift the veil on the formation of the most massive stars which remains, so far, poorly understood,” says Alana Rivera-Ingraham, who led the study while she was a graduate student in the Department of Astronomy and Astrophysics at the University of Toronto, Canada, and is currently a postdoctoral researcher at the Institut de Recherche en Astrophysique et Planétologie in Toulouse, France.

To study the formation of high-mass stars, Rivera-Ingraham and collaborators used high-quality and high-resolution far-infrared images from a space telescope launched by the European Space Agency in 2009 —the Herschel Space Observatory. This telescope’s two cameras recorded light that is not visible to the naked eye, spanning a range from infrared radiation partway to the microwave region. Exploiting these cameras, scientists including Peter Martin, Professor in the Canadian Institute for Theoretical Astrophysics at the University of Toronto, created the HOBYS Key Programme to study the birth of very massive stars in nearby giant clouds of gas and dust in our own Galaxy, including W3. Research on HOBYS at the University of Toronto is supported in part by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada.

Scientists track the regions of the gas cloud where stars are about to form by mapping the density of dust and its temperature, looking for the most dense regions where the dust is shielded and cold. “We can now see where stars are about to be born before it even happens, because we can detect the cold dust condensations,” says Martin. “Until Herschel, we could only dream of doing that.”

Stars are born in the denser parts of gas clouds, where the gas gets compressed enough by gravity to trigger nuclear fusion. The more massive the newborn star, the more visible and ultraviolet light it emits, heating up its surroundings —including the dust studied by Herschel.
“The radiation during the birth of high-mass stars is so intense that it tends to destroy and push away the material from which they need to feed for further growth,” says Rivera-Ingraham. Scientists have modeled this process and found that stars about eight times the mass of our Sun would stop growing because they run out of gas.

But astronomers do see stars that are more massive than this theoretical limit. And by looking at W3, Rivera-Ingraham and her collaborators have found clues to how this might be possible.

The researchers noticed that the densest region of the cloud, in the upper left of the image, was surrounded by a congregation of old high-mass stars. It is as if previous generations of large stars enabled the next ones to grow also massive, and close to each other. The scientists suggest that this is no coincidence: each generation of stars might have created the right conditions for another generation to grow comparably or even more massive in its midst, ultimately leading to the formation of a rare, massive cluster of high-mass stars.

Like young high-mass stars, older stars also radiate and push gas away. If such older stars happen to be arranged favorably around a major reservoir of gas, they can compress it enough to ignite new stars. The process is similar to the way a group of street cleaners armed with leaf blowers can stack leaves in a pile —by pushing from all sides at the same time. This corralling of dense gas can give birth to new, high-mass stars. A large newborn star will push its food source away, but if it is surrounded by enough large stars, these can keep nudging gas back at it. With such collective feeding at play, the young star could grow very massive indeed.

Next on the to-do list of the astronomers is to test their idea by simulating the situation with computer modeling, by measuring gas motions, and by comparing their results with data from other giant clouds studied by HOBYS. Only then will they be able to discern the mechanism —collective feeding or not— that gives rise to high-mass stars in these giant clouds.

LINKS:
UofT press release: http://universe.utoronto.ca/embargo/w3
ESA press release: http://www.esa.int/Our_Activities/Space_Science/Herschel/Hunting_high-mass_stars_with_Herschel
Official image and credits: http://oshi.esa.int/image.html?id=96

CONTACTS:
Prof. Peter Martin
Canadian Institute for Theoretical Astrophysics
University of Toronto
Toronto, Canada
pgmartin@cita.utoronto.ca

Dr. Alana Rivera-Ingraham
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Toulouse, France
arivera@irap.omp.eu

Johannes Hirn
Outreach and Communications
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
Toronto, Canada
hirn@di.utoronto.ca
(+1) 416 978 6840

Planck space mission sheds light on the universe’s age, evolution and composition

The best map ever made of the most ancient light in the universe — the remnant radiation left over from the Big Bang some 13 billion years ago — deepens our understanding of the universe.
The highly detailed image of the universe — produced by the European Space Agency’s Planck Space Telescope and the Planck collaboration of international scientists including a team from U of T — reveals that the universe is slightly older, expanding more slowly and has more matter than previously thought.
“For all of us, the magic is how we translate the observations of the spatial patterns in this ‘first light’ of the universe to the structure that must have been there in the earliest moments when our observable universe — currently some giga-giga-giga-metres across — was compressed to smaller than a nano-nano-nano metre across,” said University Professor J. Richard Bond.
Bond and Douglas Scott of the University of British Columbia co-lead a Canadian science team that played a key role in the Planck collaboration. Bond is on the faculty at the Canadian Institute for Theoretical Astrophysics and directs the Cosmology and Gravity Program of the Canadian Institute for Advanced Research (CIFAR), and the team included astrophysicists at the University of Toronto, University of Alberta, Université Laval and McGill University.
Planck’s evidence confirms and refines previous models of how astronomers believe the universe originated and evolved, but with intriguing new details:

  • The Planck team has calculated that the universe is 13.82 billion years old — 80 million years older than earlier estimates.
  • the Planck Space Telescope has revealed that the universe is expanding slower than the current standard determined with the Hubble Space Telescope.
  • Planck has also allowed cosmologists to confirm the universe’s composition more accurately than ever before: normal matter, the stuff of stars and galaxies like our own Milky Way, makes up just 4.9 per cent of the universe. Dark matter — the presence of which so far has been inferred only through the effects its gravity causes — accounts for 26.8 per cent. Dark energy — a mysterious force that behaves the opposite way to gravity, pushing and expanding our universe — makes up 68.3 per cent of the universe — slightly less than previously thought.

Planck’s precision has also given astrophysicists a number of new puzzles to solve. “For more than three decades, I have been trying to unveil the structure imprinted on the universe from an epoch of accelerated expansion in its earliest moments,” said Bond. “Planck has now shown that the evidence for this early inflation is much stronger than before. The patterns we see are quite simple, resulting in many formerly viable theories falling victim to our Planckian knife. Our maps reveal unexplained, large-scale features that excite the imaginations of physicists who have been eagerly awaiting what Planck has to say about the early universe.”
Launched in 2009, the Planck telescope has been scanning the skies ever since, shedding light on the beginnings of the universe and the birth of stars. The telescope’s incredible accuracy allows it to pinpoint faint, minute patterns — differences in light and temperature that correspond to slightly different densities in the matter left over from the Big Bang.
The data was released today at ESA headquarters in Paris, France and is from the first 15 months of the mission. It shows a map of the universe when it was just 380,000 years old.
“We now have a precise recipe for our universe: how much dark and normal matter it is made of; how fast it is expanding; how lumpy it is and how that lumpiness varies with scale; and how the remnant radiation from the Big Bang is scattered,” said University of British Columbia Professor Douglas Scott. “It is astonishing that the entire universe seems to be describable by a model using just these six quantities. Now, Planck has told us the values of those numbers with even higher accuracy.”
Twenty-eight scientific papers from the Planck mission were will be published tomorrow on-line today covering many aspects of how the universe is put together and how it has evolved. Planck’s instruments allow astronomers to separate the primordial light from the effects of dust and other emissions coming from our Milky Way Galaxy. U of T and CITA astrophysicist Peter Martin is working on a series of papers that will be published in another upcoming release on this data: “We do not simply sweep away the dust signal into the trash bin, but rather treasure it for what it tells us about the workings of the Galaxy. It enables us to discover the evolution of structure in the interstellar medium leading from a diffuse state to star formation in dense molecular clouds,” he said.
Hundreds of astronomers from around the world will continue to study Planck’s data as the telescope continues its observations.
The complete results of the mission are scheduled to be released in 2014.
In addition to Bond and Martin, the current U of T scientists in the Planck mission include CITA’s Mike Nolta and Marc Antoine Miville Deschenes (based in Paris), and Professor Barth Netterfield of the Department of Astronomy and Astrophysics who led the large software effort at UofT used to check the data as it poured in from the satellite.

The Canadian Space Agency funds two Canadian research teams who are part of the Planck science collaboration, and who helped develop both of Planck’s complementary science instruments, the High Frequency Instrument (HFI) (LINK) and the Low Frequency Instrument (LFI).

Press release issued by the University of Toronto.

Additional Links:

Distant Planetary System is Super-Sized Solar System (March 14, 2013)

TORONTO, ON (11 March 2013) – A team of astronomers, including Quinn Konopacky of the Dunlap Institute for Astronomy & Astrophysics, University of Toronto, has made the most detailed examination yet of the atmosphere of a Jupiter-like planet beyond our Solar System.

According to Konopacky, “We have been able to observe this planet in unprecedented detail because of the advanced instrumentation we are using on the Keck II telescope, our ground-breaking observing and data-processing techniques, and because of the nature of the planetary system.”

Konopacky is lead author of the paper describing the team’s findings, to be published March 14th in Science Express, and March 22nd in the journal Science.

The team, using a high-resolution imaging spectrograph called OSIRIS, uncovered the chemical fingerprints of specific molecules, revealing a cloudy atmosphere containing carbon monoxide and water vapour. “With this level of detail,” says Travis Barman, a Lowell Observatory astronomer and co-author of the paper, “we can compare the amount of carbon to the amount of oxygen present in the planet’s atmosphere, and this chemical mix provides clues as to how the entire planetary system formed.”

There has been considerable uncertainty about how systems of planets form, with two leading models, called core accretion and gravitational instability. Planetary properties, such as the composition of a planet’s atmosphere, are clues as to whether a system formed according to one model or the other.

“This is the sharpest spectrum ever obtained of an extrasolar planet,” according to co-author Bruce Macintosh of the Lawrence Livermore National Laboratory. “This shows the power of directly imaging a planetary system. It is the exquisite resolution afforded by these new observations that has allowed us to really begin to probe planet formation.”

The spectrum reveals that the carbon to oxygen ratio is consistent with the core accretion scenario, the model thought to explain the formation of our Solar System.

The core accretion model predicts that large gas giant planets form at great distances from the central star, and smaller rocky planets closer in, as in our Solar System. It is rocky planets, not too far, nor close to the star, that are prime candidates for supporting life.

“The results suggest the HR 8799 system is like a scaled-up Solar System,” says Konopacky. “And so, in addition to the gas giants far from their parent star, it would not come as a surprise to find Earth-like planets closer in.”

Konopacky and her team will continue to study the super-sized planets to learn more details about their nature and their atmospheres. Future observations will be made using the recently upgraded OSIRIS instrument which utilizes a new diffraction grating—the key component of the spectrograph that separates light according to wavelength, just like a prism. The new grating was developed at the Dunlap Institute and installed in the spectrograph in December 2012.

“These future observations will tell us much more about the planets in this system,” says Dunlap Fellow Konopacky. “And the more we learn about this distant planetary system, the more we learn about our own.”

CONTACT INFORMATION:

Dr. Quinn Konopacky
Dunlap Fellow
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
e: konopacky@dunlap.utoronto.ca
p: 416-946-5465
www.dunlap.utoronto.ca/
www.di.utoronto.ca/~konopacky

Chris Sasaki
PIO; Communications and New Media Specialist
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
e: csasaki@dunlap.utoronto.ca
p: 416-978-6613

The Dunlap Institute for Astronomy & Astrophysics continues the legacy of the David Dunlap Observatory of developing innovative astronomical instrumentation, including instrumentation for the largest telescopes in the world. The research of its faculty and Dunlap Fellows spans the depths of the Universe, from the discovery of exoplanets, to the formation of stars, the evolution and nature of galaxies, dark matter, the Cosmic Microwave Background, and SETI. The institute also continues a strong commitment to developing the next generation of astronomers and fostering public engagement in science. For more information: www.dunlap.utoronto.ca

Canada Contributes to One of Astronomy’s Most Powerful Telescopes (March 13, 2013)

On March 13 2013, the Atacama Large Millimeter/submillimeter Array (ALMA), the largest ground-based astronomical project in the world, will be inaugurated, celebrating ALMA’s transition from a construction project to a full-fledged observatory. The inauguration ceremony will take place at ALMA’s Operations Support Facility (OSF), 34 km from San Pedro de Atacama, in Chile.

 
What is ALMA?
Located at the highest and driest desert in the world (northern Chile), ALMA is one of astronomy’s most powerful telescopes, providing unprecedented imaging capabilities and sensitivity many orders of magnitude greater than anything of its kind today.

The Observatory is comprised of an array of 66 radio antennas that work together as one telescope to study millimetre- and submillimetre-wavelength light from space. These wavelengths, which cross the critical boundary between infrared and microwave radiation, hold the key to understanding such processes as the formation of planets, stars, galaxies, and of organic and other molecules in space.

 
Canada’s Contributions
Ten years ago the National Research Council of Canada agreed to design, develop and deliver seventy-three state-of-the-art receivers, operating at 3mm (100 GHz), as the major part of Canada’s contribution to the C$1.4B international ALMA radio telescope.

NRC Herzberg in Victoria, BC, is one of the few facilities in the world with expertise in superconducting detector technology for millimetre waves. These receivers are of paramount importance to the project because they are used for science applications but also for final adjustment of the antenna surfaces and for regular calibration of the array during operations.

“The receivers contributed by Canada play a critical role in the operation of ALMA. They are expected to lead directly to many discoveries ranging from images of ‘nearby’ planets, stars and gas clouds to the detection of the most distant objects in the Universe – galaxies in the early stages of their formation. They also serve as ‘work horses’ as they are used for all sorts of tests and calibrations of the system,” notes ALMA Deputy Director Lewis Ball.

The University of Calgary and McMaster University received awards from the Canada Foundation for Innovation to fund Canada’s share of the general site infrastructure costs Canadian programmers and astronomers at these universities also contributed to developing specialized code to allow astronomers to acquire and process ALMA data.

 
Can Canadian Astronomers access ALMA?
ALMA observing time is shared between all the participating countries. Canadian astronomers have access to North America’s 37.5% share of ALMA observing time. Astronomers have to submit a proposal to obtain observing time.

 
Canadian Industry Participation
Several Canadian companies provided significant contributions to NRC’s multimillion-dollar receiver program, including Nanowave Technologies of Etobicoke, ON, for the construction of the detector assemblies and the cryogenic low noise amplifiers; Daniels Electronics of Victoria, BC, for materials management and mechanical integrations; and K-Tec Industry and Prototype Equipment Design of British Columbia for providing high precision micro-machined parts. “We believe that the (cryogenic low noise amplifier) technology licensed from NRC could open up new markets for commercial and defence radar and satellite communications” says Dr. Justin Miller, President of Nanowave Technologies.

TeraXion of Quebec City, QC, won the multimillion-dollar contract from the U.S. National Radio Astronomy Observatory to provide the laser system at the heart of the ALMA signal network between the antennas and supercomputers at the 5,000 m high Array Operations Site on the Chajnantor plateau.

 
Making a Difference
Astronomers from around the world will use these Canadian-made receivers to explore in unmatched detail the evolution of cold gas and dust throughout the Universe. Early observations with the first on line receivers provided new scientific insights and Canadian Project Scientist Christine Wilson of McMaster University comments, “I found it incredibly exciting that the first image published from ALMA used data from the Canadian-built 3mm receivers. The comparison of the new ALMA image with my measurements from a decade ago was absolutely stunning – ALMA did more in 3 hours of observing than we were able to do in 100 hours.”

 
The Partnership
The Atacama Large Millimetre/submillimetre Array (ALMA) an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

 
What’s Next
Canada’s construction contributions were completed with the delivery of Band 3. Final construction of the ALMA array continues through this calendar year. As of 1 January 2014, ALMA will be considered to be fully completed and in operations, with a focus on commissioning its extensive set of capabilities. A tripartite agreement for operations is currently under development.

 
Contact:
Media Relations
National Research Council of Canada
613-991-1431
1-855-282-1637
media@nrc-cnrc.gc.ca@nrc_cnrc

Construction Begins on Canada’s Largest Radio Telescope (January 24, 2013)

Construction is now under way in Penticton, B.C. on Canada’s largest radio telescope – and the first research telescope to be built in the country in more than 30 years.

The new telescope, with a footprint larger than six NHL hockey rinks, will listen for cosmic sound waves and help scientists understand why the universe has expanded rapidly – and learn about the mysterious ‘dark energy’ that is supposedly driving the expansion.

Part of the $11-million Canadian Hydrogen Intensity-Mapping Experiment (CHIME), the radio telescope is being built at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton B.C. because the area is federally protected from radio interference.

“We plan to map a quarter of the observable universe,” says University of British Columbia astrophysicist Mark Halpern, the project’s principal investigator. “This is an ambitious, made-in-Canada endeavor.”

With no moving parts, the telescope boasts a 100-metre-by-100-metre collecting area filled with 2,560 low-noise receivers built with components adapted from the cell phone industry which, collectively, scan half of the sky every day.

“The CHIME telescope will be the most sensitive instrument in the world for this type of research and the DRAO is one of the best sites in the world for this type of research,” says UBC astrophysicist and project co-investigator Gary Hinshaw, who was in Penticton to witness the groundbreaking of the telescope’s foundation.

“This is something that our community can be really proud of.”

Signals collected by the CHIME telescope will be digitally sampled nearly one billion times per second, then processed to synthesize an image of the sky.

“We live in an expanding universe, and the discovery at the end of the 20th century that the rate of expansion is speeding up, rather than slowing down, has forced us to re-examine basic assumptions about gravity on cosmic scales, and what the universe is made of,” says UBC astrophysicist and CHIME co-investigator Kris Sigurdson.

“It appears to be filled with an exotic substance we call dark energy.”

Adds Halpern: “Data collected by CHIME will help us understand the history of the Universe, and in turn how dark energy has driven its expansion.”

CHIME is funded in part by a $4.6-million investment from the Canada Foundation for Innovation. Astrophysicists at UBC, McGill University, the University of Toronto and the DRAO are collaborating on the project.

Original Press release available at http://science.ubc.ca/news/679

Photographs from today’s groundbreaking are available at:http://www.publicaffairs.ubc.ca/?p=78185



Press release from the University of Toronto.

TORONTO, ON (Wednesday, January 31, 2013) –

A team of Canadian astrophysicists is set to begin mapping the largest volume of the observable Universe to date. By observing hydrogen gas from seven to ten billion light-years away across a great swath of sky, their goal is to measure the accelerating expansion of the Universe and the force behind that expansion, dark energy.

The team’s work will shed light on the expansion history of the Universe after the inflationary period leading to the Big Bang and the emission of the microwave background, and before the current accelerated expansion.

“By observing the expansion of the Universe, we will be able to make precise measurements of dark energy,” Prof. Ue-Li Pen from the University of Toronto and the Canadian Institute for Theoretical Astrophysics (CITA) said. “They will allow us to determine whether dark energy is changing with time or whether it is a constant. (And what does this tell us. C.S.)”

The team includes Pen, Prof. Dick Bond of the University of Toronto and CITA, and Prof. Keith Vanderlinde of the Dunlap Institute for Astronomy & Astrophysics, as well as astrophysicists from UBC, McGill and the Dominion Radio Astronomy Observatory (DRAO). The group recently received $4.6 million in funding from the Canadian Foundation for Innovation to build an innovative digital radio telescope at the DRAO in the Okanagan Valley near Penticton, B.C. The instrument is known as the Canadian Hydrogen Intensity Mapping Experiment (CHIME) and will have a surface area greater than six NHL hockey rinks.

Bond explained, “the origin of accelerated expansion is inextricably tied to how gravity interacts with the ‘vacuum energy’ whose nature has been the greatest mystery in physics for eighty years. For CITA theorists the exciting data that will emerge is a rich treasure trove.”

“This research requires a new kind of telescope, which only recently became possible thanks to the huge growth in computing power,” Vanderlinde said. “CHIME will be the country’s largest radio telescope and survey the sky hundreds of times more efficiently than previous instruments.”

CHIME will chart the expansion beginning in the period when cosmic acceleration appears to have turned on, from something like 11 billion years ago (redshift 2.5) until ~6.5 billion years ago (redshift 0.8) .

The ambition is large. “We’ve been mapping the universe for a hundred years since Edwin Hubble and to date we’ve mapped maybe one per cent of that, and CHIME wants to map about a quarter of the observable universe”, Pen said.

CHIME will use a new technique called Hydrogen Intensity Mapping pioneered by a team led by Pen, which allows a radio telescope to map the structure of the universe in neutral hydrogen gas directly using radio observations, rather than using optical telescopes to methodically catalogue each galaxy. It allows astrophysicists to survey huge volumes of the universe in three dimensions, and for a fraction of the cost of other methods.

“Hydrogen Intensity Mapping will have many applications,” said Vanderlinde, “but the main goal for CHIME is to amass data on the evolution of the universe, to probe what is accelerating its expansion. CHIME promises to reveal cosmic acceleration in unprecedented detail”.

The experiment will use a new hybrid of both digital and analog radio telescope technology. A traditional telescope’s parabolic dish must be pointed. A digital software telescope has no curvature, no preferred direction, and is simultaneously pointed in all directions of the sky at the same time, Pen explained, “which is pretty sweet, obviously”.

CHIME will be built at the Dominion Radio Astronomy Observatory sheltered in the Okanagan Valley near Penticton, British Columbia on a radio-quiet reserve protected from local radio-frequency interference by federal regulation and the surrounding hills. It will be a set of five 100-metre long x 20 metre half-pipes, lying side by side in a 100 metre-square array constructed of metal roofing struts, concrete legs and wire mesh, and will have no moving parts. It will work digitally in the North-South direction along the length of the half pipes, and will work as a traditional analog telescope in the East-West direction. It will scan the sky above it in a line from horizon to horizon as the earth turns every day, and stack the data it collects.

Bond is also and Director of the Canadian Institute for Advanced Research (CIFAR), cosmology and gravity program. He said “the great collaboration of CITA with the Canadian Institute for Advanced Research, Cosmology and Gravity Program and its cross-Canada nodes extends to our CHIME initiative.” The CIFAR Cosmology and Gravity Program members engaged are: two CIFAR Fellows at CITA, Ue-Li Pen and Bond, one Fellow at McGill, Matt Dobbs, two Fellows at UBC, Gary Hinshaw and Mark Halpern and one member of the CIFAR Junior Fellow Academy at the Dunlap Institute and the Department of Astronomy and Astrophysics, U of T, Keith Vanderlinde. As well, CITA Post Doctoral Fellows and graduate students are involved in CHIME research.

The CFI funded CHIME through its Leading Edge Fund which invests in state-of-the-art infrastructure for Canada’s research institutions to attract and retain world-class talent and train a new generation of researchers.

For Further Information contact,
Alison Rose, O.Ont.
Outreach & Communications Coordinator
Canadian Institute for Theoretical Astrophysics (CITA)
www.cita.utoronto.ca
cell 416-997-1625 aer@cita.utoronto.ca


Chris Sasaki
Communications & New Media Specialist
Dunlap Institute for Astronomy & Astrophysics
416-978-6613 csasaki@di.utoronto.ca
www.dunlap.utoronto.ca

Additional Resources:

Astronomers Discover Star With the Shortest Orbital Period Around Milky Way Galaxy’s Central Black Hole (October 4, 2012)

TORONTO, ON (Tuesday, 2 October 2012) – A team from UCLA that includes an astronomer with the Dunlap Institute, University of Toronto, has discovered a star that orbits the supermassive black hole at the centre of the Milky Way Galaxy in less time than any other known star.

Referred to as S0-102, the star circuits our galaxy’s centre in 11.5 years, or less time than Jupiter takes to orbit the Sun. According to the Dunlap’s Tuan Do, “Because of its proximity to the central black hole, S0-102 gives us an excellent opportunity to test Einstein’s General Relativity.”

The team’s findings will be published in the journal Science on Friday, 5 October 2012. They are the latest results from the 17-year effort of the UCLA Galactic Center Group, led by Prof. Andrea Ghez of the Department of Physics & Astronomy.

It was by studying the stars in the Milky Way Galaxy’s central region that Ghez and her team originally discovered the supermassive black hole in the heart of our galaxy. Known as Sgr A* (Sagittarius A-star), the prodigious object contains the mass of four million stars equal in mass to our Sun. “Having proved that black holes exist,” says Ghez, “our research today aims to understand their nature and how they warp space and time.”

There are thousands of stars within a few light-years of our galaxy’s centre. As Do, a co-author on the Science paper, describes it, “This region is the most extreme environment in the galaxy. It has the highest density of stars—equivalent to having over a million stars between the Sun and our next closest star, Alpha Centauri. The stars closest to Sgr A* are travelling at over 4000 kilometres per second. That’s 1% the speed of light.”

The previous stellar record holder for orbiting Sgr A* was a star called S0-2 with a galactic orbital period of 16 years. According to General Relativity, the elliptical orbits of objects like S0-2 and S0-102 should themselves “rotate”, creating a rosette-pattern over time. This motion is known as precession and is most easily observed in bodies orbiting close to massive objects.

But the mass of other stars near the galaxy’s centre creates a different type of precession which is hard to separate from precession caused by General Relativity. By studying the orbits of S0-02 and S0-102 together, the Galactic Center Group will be able to distinguish between the two precessions. And according to Ghez, “It is conceivable that we will be able to observe deviations from Einstein’s theory in regions where S0-102 and other short period stars reside.”

S0-102 was discovered using images taken with the twin 10-metre telescopes of the Keck Observatory on Mauna Kea in Hawai’i. These included observations with the Keck II telescope using adaptive optics and laser guide-star technology which corrects for distortions caused by the Earth’s atmosphere. With a resolution greater than that of the Hubble Space Telescope, the observations allow Ghez, Do and the group to resolve individual stars in the crowded region.

Do joined the Dunlap Institute for Astronomy & Astrophysics, University of Toronto, in August 2012, where he will continue to work with the UCLA group in preparation for observations of the galactic centre using the next generation Thirty Meter Telescope (TMT). Scheduled to begin operation later this decade, the TMT will not only substantially improve the measurements for S0-102; the group fully expects that it will also lead to the discovery of many, even shorter-period stars.

CONTACT INFORMATION:

Dr. Tuan Do
Dunlap Fellow
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
e: do@dunlap.utoronto.ca
p: 416-78-2215
www.dunlap/utoronto.ca/dr-tuan-do
www.di.utoronto.ca/~do

Chris Sasaki
PIO, Communications and New Media Specialist
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
e: csasaki@dunlap.utoronto.ca
p: 416-978-6613

Prof. Andrea Ghez
Principal Investigator
UCLA Galactic Center Group
Department of Physics & Astronomy
UCLA
e: ghez@astro.ucla.edu
p: 310-206-0420

About the Dunlap Institute for Astronomy & Astrophysics, University of Toronto: The Dunlap Institute was established in May 2008 at the University of Toronto, creating a dynamic centre for astronomical research along with the university’s Department of Astronomy & Astrophysics and Canadian Institute for Theoretical Astrophysics. The Dunlap Institute continues the legacy of the David Dunlap Observatory of developing innovative astronomical instrumentation, including instrumentation for the largest telescopes in the world. The research of its faculty and Dunlap Fellows spans the depths of the Universe, from the discovery of exoplanets around nearby stars, to star formation, black holes, dark matter, high-redshift galaxies, and the Big Bang. The institute also continues a strong commitment to developing the next generation of astronomers through education programs, and fostering public engagement in science through a wealth of outreach activities.

For more information about the Dunlap Institute: www.dunlap.utoronto.ca

A Grand Design Spiral Galaxy Before Its Time

TORONTO, ON (12 JULY 2012) – A team led by an astronomer at the Dunlap Institute for Astronomy & Astrophysics, University of Toronto, has discovered a spiral galaxy that appears to have formed a billion years before other spirals. The galaxy is 10.5 billion light-years from Earth, putting it at a time when the Universe was only three billion years old and spirals were extremely rare.

According to Dunlap Institute postdoctoral fellow and Principal Investigator David Law, “Seeing this galaxy amongst the irregular, young galaxies of that epoch is like seeing a fully-formed adult in a room of grade-school children.”

Law says, “The fact that this galaxy exists is astounding. Current wisdom holds that such grand-design spiral galaxies simply didn’t exist at such an early time in the history of the Universe.” Most galaxies in the three billion year old Universe are clumpy and irregularly-shaped; they haven’t formed the well-defined spiral arms we see in galaxies like the iconic M51 Whirlpool Galaxy.

The rest of Law’s team comprises researchers from UCLA, Caltech, UC Riverside, Steward Observatory, and UW Milwaukee. The Space Telescope Science Institute provided principal funding for the work, the results of which will be published in the 19 July 2012 issue of the science journal Nature.

The researchers noticed the galaxy, identified as BX442, in images they obtained using the Hubble Space Telescope (HST). Law’s co-investigator Alice Shapley, from UCLA, remembers coming across the galactic oddity. “Among the irregular and clumpy galaxies of the early Universe, this well-ordered spiral stuck out like a sore thumb—a beautiful and amazing sore thumb.”

But, while the Hubble image revealed the galaxy’s spiral structure, it didn’t prove conclusively that the galaxy rotated. In order to settle this question, Law and Shapley used the Keck II telescope in Hawaii to study the object’s internal motions. The twin Keck telescopes, each with 10-metre diameter primary mirrors, are the largest optical/infrared telescopes in the world. The Keck II is equipped with a laser-guide-star adaptive-optics system which corrects for the distortion of in-coming light caused by the Earth’s turbulent atmosphere, resulting in images as sharp as those taken with the HST.

Law and Shapley used an integral-field spectrograph called OSIRIS (OH-Suppressing Infrared Imaging Spectrograph) on the Keck II telescope to sample light from different parts of the galaxy. These samples showed that those parts were moving at different speeds relative to us—revealing that it is indeed a spiral disk, rotating roughly as fast as our own Milky Way Galaxy, but much thicker and forming stars more rapidly.

While the spiral structure and rotation have been confirmed, the reason for the spiral structure remains a mystery; it’s unclear why this galaxy has been able to form such sweeping spiral structures so much earlier than other galaxies. According to Shapley, “Immediately, we started wondering how such a spiral galaxy might form in the early universe.” One possibility, Law suggests, is the presence of a dwarf companion galaxy that they observe in the process of merging with the main galaxy. Just as Messier 51 is subject to tidal forces from a dwarf companion of its own, gravitational interaction with the newly-discovered galaxy’s dwarf companion might help excite transient spiral structure within the main galaxy. Understanding this mechanism in greater detail could help explain the formation and evolution of modern spirals like our own Milky Way Galaxy.

CONTACT INFORMATION:

Dr. David Law, Lead Author/Principal Investigator
Dunlap Fellow
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
email: drlaw@dunlap.utoronto.ca
phone: 416-946-5435
www.dunlap.utoronto.ca/david-law/
www.di.utoronto.ca/~drlaw

Chris Sasaki
PIO, Communications and New Media Specialist
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
email: csasaki@dunlap.utoronto.ca
phone: 416-978-6613

About the Dunlap Institute for Astronomy & Astrophysics, University of Toronto: The Dunlap Institute was established in May 2008 at the University of Toronto, creating a dynamic centre for astronomical research along with the university’s Department of Astronomy & Astrophysics and Canadian Institute for Theoretical Astrophysics. The Dunlap Institute continues the legacy of the David Dunlap Observatory of developing innovative observational techniques, instruments, telescopes and observatories—including instrumentation for the largest telescopes in the world. The research of its faculty and postdoctoral fellows spans the depths of the Universe, from the discovery of planets around nearby stars, to black holes, dark matter, and the study of galaxies at the beginning of time. The institute also continues a strong commitment to developing the next generation of astronomers through education programs, and passionately fostering public engagement in science through a wealth of outreach activities.