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:

Public Release of SCUBA-2 Commissioning Data (January 15, 2013)

During the astronomical commissioning of SCUBA-2 in 2011, several sources were observed mostly for observing mode testing, array performance improvements and telescope integration. The absolute quality of the data cannot be vouched for, and the weather conditions and the array stability may be variable. Nevertheless, the data are of sufficient quality that they may be of scientific interest to some. As such these data are being publicly released. The catalogue of publicly released SCUBA-2 commissioning data is available via the JCMT Science Archive at the CADC.

Ring Around Andromeda Challenges Galactic Ideas (January 3, 2013)

A surprising discovery about dwarf galaxies orbiting the much larger Andromeda galaxy suggests that conventional ideas regarding the formation of galaxies like our own Milky Way are missing something fundamental.

In a paper published today in the prestigious journal Nature, an international team of astronomers including two University of Victoria professors describes the discovery that almost half of the 30 dwarf galaxies orbiting Andromeda do so in an enormous plane more than a million light years in diameter, but only 30,000 light years thick.

The findings defied scientists’ expectation—based on two decades of computer modeling—that satellite galaxies would orbit in independent, seemingly random patterns. Instead, many of these dwarf galaxies seem to share a common orbit, an observation that currently has no explanation.

“It’s a very unusual, unexpected configuration,” says UVic astrophysicist Dr. Julio Navarro, a co-author of the paper. “It’s so unexpected that we don’t know yet what it’s telling us. The fact that it is there at all is pointing us toward something profound.”

The paper is based on data collected as part of a project led by UVic adjunct assistant professor Dr. Alan McConnachie, of the National Research Council of Canada’s Herzberg Institute of Astrophysics (NRC-HIA) in Saanich. McConnachie, another co-author of the Nature paper, is principal investigator of the Pan Andromeda Archaeological Survey (PAndAS), which used the Canada-France-Hawaii Telescope between 2008 and 2011. Examination of the data collected provided the first panoramic view of the Andromeda galaxy, the Milky Way’s nearest galactic companion, and the surprising discovery.

Understanding how and why the dwarf galaxies form the ring around Andromeda is expected to offer new information on the formation of all galaxies.

 
Media Contacts:
Dr. Alan McConnachie (National Research Council of Canada) at 250-363-0070 (alan.mcconnachie@nrc-cnrc.gc.ca)
Dr. Julio Navarro (Faculty of Science) at 250-721-6644 or jfn@uvic.ca
Mitch Wright (UVic Communications) at 250-721-6139 or mwwright@uvic.ca

3D Simulations of Supernova Remnants (November 5, 2012)

An international team of astrophysicists, including Drs. Samar Safi-Harb and Gilles Ferrand at the University of Manitoba (Canada) and Dr. Anne Decourchelle from the CEA Saclay (France), has produced the first 3D simulations of supernova remnants (SNRs) showing the effect of particle acceleration at the wave fronts generated by these powerful X-ray sources in our galaxy. The research has been just published in the Astrophysical Journal.

Safi-Harb notes: “With these simulations, we are generating the first realistic synthetic maps of projected thermal x-ray emission in young SNRs.” Decourchelle adds: “This opens a new way to understand the physics at play by confronting high resolution 3D simulations to detailed X-ray observations of SNRs.”

They note that the results will impact on astrophysicists’ interpretations of high-resolution x-ray observations, such as those currently underway using the orbiting Chandra and XMM-Newton x-ray observatories (launched in 1999 by NASA and ESA, respectively), or those planned with Astro-H (slated for launch by JAXA in 2014).

One hundred years ago, Austrian physicist Victor Hess detected cosmic rays using a high-altitude balloon. Their origin has been a puzzle since then, but astronomers have suggested that most of these particles are accelerated by fast-moving shock waves triggered by supernova explosions. Recent x-ray and gamma-ray studies have supported this theory, but astrophysicists are not sure if protons (which make the bulk of the cosmic rays population) are also accelerated and to what energy levels. Since magnetic fields affect the flight of cosmic rays, they arrive on earth from all directions, making it difficult to determine their origin.

It is, however, possible to observe their likely sources in the galaxy: the SNRs, and look for signatures of their presence. The new simulations show how the efficient acceleration of particles at the shock affects both the shape and the level of x-ray emission from SNRs.

Ferrand, lead author of the paper, says: “These 3D simulations, the first of their kind, will help us to unveil the presence of very energetic protons in young SNRs.”

This research was made possible by using a computer cluster devoted to these unique simulations and funded by the Canada Foundation for Innovation, as well as a supercomputer at CEA/CCRT in France. It was also supported by funds from the Natural Sciences and Engineering Research Council (NSERC) Canada Research Chair program, the Canadian Institute for Theoretical Astrophysics (CITA) and the French National Research Agency (ANR).

For more information, please contact Samar Safi-Harb, Canada Research Chair in Supernova Astrophysics, University of Manitoba, at: 204-474-7104, or email: samar.safi-harb@ad.umanitoba.ca

In France, contact: Anne Decourchelle, 33 2 69 08 43 84, or email: anne.decourchelle@cea.fr

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.