CFHT Uncovers Large Number of Dark Matter Peaks Using Gravitational Lensing (July 15, 2014).

A number of studies have shown that Dark Matter is the principal mass component of the Universe making up about 80% of the mass budget. The most direct technique to reveal the Dark Matter distribution is by using the gravitational lensing technique. Indeed, following Einstein’s theory of Gravitation, we know that a mass concentration will deform locally the Space-Time and the observed shapes of distant galaxies seen through the such concentration will be deflected and distorted. By measuring the exact shapes of millions of these distant galaxies we can then map accurately the mass distribution in the Universe, and identify the mass peaks tracing mass concentration along their line of sight. Importantly, the number of mass peaks as a function of the mass peak significance encodes important information on the cosmological world model. In particular this distribution is sensitive to the nature of Gravitational force at large scales as well as the geometry of the Universe. Measuring mass peaks is thus one of the most attractive way to probe the relative importance and nature of Dark Matter and Dark Energy, measure the evolution the Universe and predict its fate.

In a new publication of the Monthly Notice of Royal Astronomical Society, an international team, comprising researchers from Swiss, France, Brazil, Canada, and Germany present the first detailed analysis of the weak lensing peaks. This work is considered as a milestone, given the possible importance of the weak lensing peaks for cosmology. Because mass peaks are identified in two–dimensional dark matter maps directly, they can provide constraints that are free from potential selection effects and biases involved in identifying and measuring the masses of galaxy clusters. In fact a small fraction of the max peaks are just mass concentration excess along the line of sight, and not genuine massive clusters.

To detect the weak lensing mass peaks, the research team used the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82 in short), still one of the largest weak lensing survey yet. The Survey covers ~170 square degrees of the Stripe 82 of the Sloan Digital Sky Survey (SDSS), an equatorial region of the South Galactic Cap that has been extensively studied by the SDSS project. With the precise shape measurement for more than four million faint distant galaxies, a dark matter mass map was generated. Huan Yuan Shan, the lead author of this publication explains that: “By studying the mass peaks in the map, we found that the abundance of mass peaks detected in CS82 is consistent with predictions from a ΛCDM cosmological model. This result confirms that the dark matter distribution from weak lensing measurement can be used as a cosmological probe”.

Jean-Paul Kneib, co-author of the publication explains that: “This work opens a new window to constrain cosmology with weak gravitational lensing. We can not only reveal where the dark matter is located using space-time distortion, but also use the distributions of mass peaks to better constrain and understand our Universe”.

Huan Yuan Shan, adds that: “Because of their large number, the small mass peaks in the Dark Matter maps contain more resolving power than the most massive peaks to constrain cosmological models”. As a cosmological probe, the weak lensing mass peak abundance is very complementary to the other cosmology probes, such as the study of the Cosmological Microwave Background (CMB), the study of distant SuperNovae, the measure of the Baryonic Accoustic Oscillation and the cosmic shear.

The abundance of mass peaks in the Dark Matter mass map confirms the theories of structure formation. In the near future, with the up-coming weak lensing surveys (to be conducted with the DES survey, LSST and Euclid), by precisely counting the peaks of dark matter mass maps, we will be able to set constrains on the nature of Dark Matter and Dark Energy.

About the CFHT Stripe 82 survey:

The CFHT Stripe 82 (CS82) collaboration comprises scientists from the following institutions: University of British Columbia (Canada), Laboratoire d’Astrophysique de Marseille (France), Brazilian Center for Physics Research (Brazil), École Polytechnique Fédérale de Lausanne (Switzerland), Institute for the Physics and Mathematics of the Universe (Japan), Universität Bonn (Germany), Institut d’Astrophysique de Paris (France), Valongo Observatory/Federal University of Rio de Janeiro (Brazil), Instituto de Astronomia, Geofísica e Ciências Atmosféricas – USP (Brazil), Instituto de Física – UFRGS (Brazil), Observatório Nacional (Brazil), Universitá deli studi di Ferrara (Italy), University of Hertfordshire (UK), University of Oxford (UK), University College London (UK), University of Waterloo (Canada), Leiden Observatory (Netherlands), Lawrence Berkeley National Laboratory (USA), University of California Berkeley (USA), Stanford (USA).

The CS82 survey is based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l’Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. The Brazilian partnership on CFHT is managed by the Laboratório Nacional de Astrofísica (LNA). We thank the support of the Laboratório Interinstitucional de e-Astronomia (LIneA). We thank the CFHTLensS team through the expertise they built in analysing CFHT/Megacam weak lensing data.

ADS link to the paper

Contact information:
Dr. HuanYuan Shan
Affiliation: EPFL, Switzerland
Phone number: +41 22 379 2427
huanyuan.shan@epfl.ch

Prof. Jean-Paul Kneib.
Affiliation: EPFL, Switzerland
Phone number +33 695 795 392
jean-paul.kneib@epfl.ch

Prof. Martin Makler.
Affiliation: CBPF, Brazil
Phone number +55 21 2141 7191
martinmakler@gmail.com

Prof. Ludovic van Waerbeke
Affiliation: UBC, Canada
Phone number +1 604 822 5515
waerbeke@physics.ubc.ca

Dr. Eric Jullo.
Affiliation: LAM, France
Phone number +33 491 05 59 51
eric.jullo@lam.fr

Dr. Daniel Devost
Director of Science Operations
Phone: (808)885-3163
devost@cfht.hawaii.edu

TMT Exhibits a Next-Generation Telescope Mirror Assembly in Canada (June 9, 2014)

The Thirty Meter Telescope (TMT) project will unveil a polished mirror assembly – a key piece of astronomy’s next-generation telescope – at the 2014 annual meeting of the Canadian Astronomical Society (CASCA). The assembly will be unveiled at a reception at 5:30pm EDT, Monday, June 9 at the Hotel Chateau Laurier, in Quebec City, Canada.

The assembly is a demonstration model of just one of the 492 mirror segments that will ultimately comprise TMT’s giant 30-meter primary mirror. TMT is a revolutionary telescope slated to begin operations in Hawaii in the 2020s.

“We are delighted that the first presentation of these sophisticated mirror assemblies is happening right here at CASCA 2014,” said Laura Ferrarese, CASCA president. “For the past decade, the Thirty Meter Telescope has been the top priority for the Canadian astronomical community, and we have worked tirelessly with our international partners to design this marvel of engineering. The science TMT will deliver will be transformative for astronomy, in Canada and worldwide.”

The polished mirror assembly displayed at CASCA, though a prototype, has nearly all of the features of a production version. The hexagonal 1.44-meter diameter mirror is made of a 45-millimeter-thick ClearCeram glass produced by the Japanese company OHARA and procured by TMT’s Canadian partners. The glass has “zero expansion” properties, meaning it retains its precise figure irrespective of changes in temperature. Within the mirror’s support assembly, 21 actuators can fine-tune the mirror’s shape for optimal telescope performance. The prototype assembly weighs about 220 kilograms.

“Given the extensive involvement by Canadian scientists and engineers in the technology development of TMT, it is fitting to offer the world a first look at a polished mirror assembly—the application of all that hard work—right here in Quebec City,” said Ernie Seaquist, executive director of the Association of Canadian Universities for Research in Astronomy (ACURA). An organization of 20 universities dedicated to the advancement of university research in astronomy and astrophysics in Canada, ACURA is an associate of the TMT project and one of its original members.

The production segments will include an extremely reflective mirror coating, and edge sensors that sense the height and tilt of neighboring mirror segments, allowing for precise positioning of each segment relative to the other segments. Together, 492 of these mirrors will work together as a single optical surface comprising TMT’s 30-meter-diameter primary mirror.

“Being able to showcase this polished mirror assembly to the scientific community and the general public is very rewarding,” said Eric Williams, the Optics Group leader for TMT. Williams has been working on designing and testing elements of the assembly for nine years.

TMT is identified as the highest priority project by CASCA in “Unveiling the Cosmos: A Vision for Canadian Astronomy, Report of the Long Range Plan 2010 Panel”. This plan, released in 2011, is the result of a detailed survey of the challenges and opportunities over the 2010-20 decade.

Through ACURA universities with support from the Federal Granting Councils, the National Research Council of Canada, and provincial funding, the Canadian astronomical community has contributed important work to TMT over the last decade in two key development areas.

Canada has been designing the telescope facility’s large aerodynamic enclosure. The innovative enclosure design features a circular opening that minimizes the wind-induced vibrations of the telescope structure while optimizing air-flow around the building to reduce distortion of the light collected by the telescope’s giant mirror. The contractor for the enclosure work is Dynamic Structures Ltd., based in Port Coquitlam, British Columbia, whose parent holding company is the Canadian firm Empire Industries Ltd.

Another major Canadian initiative has been the development of TMT’s “adaptive optics” system, called the Narrow Field Infrared Adaptive Optics System (NFIRAOS). Adaptive optics removes the blurring effects of the Earth’s atmosphere, greatly increasing the acuity of astronomical images and allowing astronomers to study very faint and distant objects in the universe.

To date, Canada has invested more than $30 million in TMT. The TMT project plans to begin construction later this year. As an Associate in the TMT International Observatory, Canada continues to be engaged in the project.

CASCA Contacts:
Leslie Sage
CASCA Press Officer
+1 (301) 675 8957
cascapressofficer@gmail.com

Laura Ferrarese
CASCA President
casca-president@casca.ca

TMT Contact:
Gordon K. Squires
TMT Communications Lead
+1 (626) 216 4257
squires@tmt.org

More information about TMT:
tmt.org

Odd planet, so far from its star… (May 13, 2014)

An international team led by Université de Montréal researchers has discovered and photographed a new planet 155 light years from our solar system.

MONTRÉAL, May 13, 2014 – A gas giant has been added to the short list of exoplanets discovered through direct imaging. It is located around GU Psc, a star three times less massive than the Sun and located in the constellation Pisces. The international research team, led by Marie-Ève Naud, a PhD student in the Department of Physics at the Université de Montréal, was able to find this planet by combining observations from the the Gemini Observatories, the Observatoire Mont-Mégantic (OMM), the Canada-France-Hawaii Telescope (CFHT) and the W.M. Keck Observatory.

A distant planet that can be studied in detail

GU Psc b is around 2,000 times the Earth-Sun distance from its star, a record among exoplanets. Given this distance, it takes approximately 80,000 Earth years for GU Psc b to make a complete orbit around its star! The researchers also took advantage of the large distance between the planet and its star to obtain images. By comparing images obtained in different wavelengths (colours) from the OMM and CFHT, they were able to correctly detect the planet.

“Planets are much brighter when viewed in infrared rather than visible light, because their surface temperature is lower compared to other stars,” says Naud. “This allowed us to indentify GU Psc b.”

Knowing where to look

The researchers were looking around GU Psc because the star had just been identified as a member of the young star group AB Doradus. Young stars (only 100 million years old) are prime targets for planetary detection through imaging because the planets around them are still cooling and are therefore brighter. This does not mean that planets similar to GU Psc b exist in large numbers, as noted by by Étiene Artigau, co-supervisor of Naud’s thesis and astrophysicist at the Université de Montréal. “We observed more than 90 stars and found only one planet, so this is truly an astronomical oddity!”

Observing a planet does not directly allow determining its mass. Instead, researchers use theoretical models of planetary evolution to determine its characteristics. The light spectrum of GU Psc b obtained from the Gemini North Observatory in Hawaii was compared to such models to show that it has a temperature of around 800°C. Knowing the age of GU Psc due to its location in AB Doradus, the team was able to determine its mass, which is 9-13 times that of Jupiter.

In the coming years, the astrophysicists hope to detect planets that are similar to GU Psc but much closer to their stars, thanks, among other things, to new instruments such as the GPI (Gemini Planet Imager) recently installed on Gemini South in Chile. The proximity of these planets to their stars will make them much more difficult to observe. GU Psc b is therefore a model for better understanding these objects.

“GU Psc b is a true gift of nature. The large distance that separates it from its star allows it to be studied in depth with a variety of instruments, which will provide a better understanding of giant exoplanets in general,” says René Doyon, co-supervisor of Naud’s thesis and OMM Director.

The team has started a project to observe several hundred stars and detect planets lighter than GU Psc b with similar orbits. The discovery of GU Psc, a rare object indeed, raises awareness of the significant distance that can exist between planets and their stars, opening the possibility of searching for planets with powerful infrared cameras using much smaller telescopes such at the one at the Observatoire du Mont-Mégantic. The researchers also hope to learn more about the abundance of such objects in the next few years, in particular, using GPI instruments, the CFHT’s SPIRou, and the James Webb Space Telescope’s FGS/NIRISS.

 

About the study

The article Discovery of a Wide Planetary-Mass Companion to the Young M3 Star GU Psc will be published in The Astrophysical Journal on May 20, 2014. The team, led by Marie-Ève Naud, doctoral student at the Department of Physics of the Université de Montréal and member of the CRAQ, consisted mainly of UdeM students and researchers, including Étienne Artigau, Lison Malo, Loïc Albert, René Doyon, David Lafrenière, Jonathan Gagné, and Anne Boucher. Collaborators from other institutions also participated, including Didier Saumon, Los Alamos National Laboratory, New Mexico; Caroline Morley, UC Santa Cruz, California; France Allard and Derek Homeier, Centre for Astrophysical Research, Lyon, France; and Christopher Gelino and Charles Beichman, Caltech, California. The study was made possible with funding from the Fonds de recherche du Québec – Nature et technologies and the Natural Sciences and Engineering Research Council of Canada.

See the article in The Astrophysical Journal

About the CRAQ

The Centre for Research in Astrophysics of Québec is a partnership between the Université de Montréal, McGill University, and the Université Laval. The CRAQ brings together all researchers working in the field of astronomy and astrophysics of these three institutions, as well as other collaborators from Bishop’s University, the Canadian Space Agency, the Cégep de Sherbrooke, and the private sector (Photon etc., ABB Bomem Inc., Nüvü Caméras). The CRAQ is funded through the program Regroupements stratégiques of the Fonds de recherche du Québec – Nature et technologies (FRQ-NT). The CRAQ constitutes a unique grouping of researchers in astrophysics in Québec bent on excellence and whose varying and complementary fields of expertise allows them to be innovative, creative and competitive in several scientific fields, thus offering graduate students a wide variety of subjects in both fundamental and applied fields of research.

Additional information

 

 

Sources:

Marie-Ève Naud
CRAQ – Université de Montréal
514 343-6111, ext 3797
naud@astro.umontreal.ca

René Doyon
Director, Observatoire du Mont-Mégantic
Professor, Department of Physics
CRAQ – Université de Montréal
514 343-6111, ext 3204
doyon@astro.umontreal.ca

Information:

Olivier Hernandez, Ph. D.
CRAQ – Université de Montréal / Head of Media Relations
514 343-6111, ext 4681 | olivier@astro.umontreal.ca | @OMM_Officiel  | @CRAQ_Officiel

‘Death Stars’ in Orion Blast Planets before They Even Form (March 13, 2014)

The Orion Nebula is home to hundreds of young stars and even younger protostars known as proplyds. Many of these nascent systems will go on to develop planets, while others will have their planet-forming dust and gas blasted away by the fierce ultraviolet radiation emitted by massive O-type stars that lurk nearby.

A team of astronomers from Canada and the United States has used the Atacama Large Millimeter/submillimeter Array (ALMA) to study the often deadly relationship between highly luminous O-type stars and nearby protostars in the Orion Nebula. Their data reveal that protostars within 0.1 light-years (about 600 billion miles) of an O-type star are doomed to have their cocoons of dust and gas stripped away in just a few millions years, much faster than planets are able to form.

“O-type stars, which are really monsters compared to our Sun, emit tremendous amounts of ultraviolet radiation and this can play havoc during the development of young planetary systems,” remarked Rita Mann, an astronomer with the National Research Council of Canada in Victoria, and lead author on a paper in the Astrophysical Journal. “Using ALMA, we looked at dozens of embryonic stars with planet-forming potential and, for the first time, found clear indications where protoplanetary disks simply vanished under the intense glow of a neighboring massive star.”

Many, if not all, Sun-like stars are born in crowded stellar nurseries similar to the Orion Nebula. Over the course of just a few million years, grains of dust and reservoirs of gas combine into larger, denser bodies. Left relatively undisturbed, these systems will eventually evolve into fully fledged star systems, with planets – large and small – and ultimately drift away to become part of the galactic stellar population.

Astronomers believe that massive yet short-lived stars in and around large interstellar clouds are essential for this ongoing process of star formation. At the end of their lives, massive stars explode as supernovas, seeding the surrounding area with dust and heavy elements that will get taken up in the next generation of stars. These explosions also provide the kick necessary to initiate a new round of star and planet formation. But while they still shine bright, these larger stars can be downright deadly to planets if an embryonic solar systems strays too close.

“Massive stars are hot and hundreds of times more luminous than our Sun,” said James Di Francesco, also with the National Research Council of Canada. “Their energetic photons can quickly deplete a nearby protoplanetary disk by heating up its gas, breaking it up, and sweeping it away.”

Earlier observations with the Hubble Space Telescope revealed striking images proplyds in Orion. Many had taken on tear-drop shapes, with their dust and gas trailing away from a nearby massive star. These optical images, however, couldn’t reveal anything about the amount of dust that was present or how the dust and gas concentrations changed in relation to massive stars.

The new ALMA observations detected these and other never-before-imaged proplyds, essentially doubling the number of protoplanetary disks discovered in that region. ALMA also could see past their surface appearance, peering deep inside to actually measure how much mass was in the proplyds.
Combining these studies with previous observations from the Submillimeter Array (SMA) in Hawai‛i, the researchers found that any protostar within the extreme-UV envelope of a massive star would have much of its disk of material destroyed in very short order. Proplyds in these close-in regions retained only a fraction (one half or less) of the mass necessary to create one Jupiter-sized planet. Beyond the 0.1 light-year radius, in the far-UV dominated region, the researchers observed a wide range of disk masses containing anywhere for one to 80 times the mass of Jupiter. This is similar to the amount of dust found in low-mass star forming regions.

“Taken together, our investigations with ALMA suggest that extreme UV regions are not just inhospitable, but they’re downright hazardous for planet formation. With enough distance, however, it’s possible to find a much more congenial environment,” said Mann. “This work is really the tip of the iceberg of what will come out of ALMA; we hope to eventually learn how common solar systems like our own are.”

Other researchers involved in this project include Doug Johnstone, National Research Council of Canada; Sean M. Andrews, Harvard-Smithsonian Center for Astrophysics; Jonathan P. Williams, University of Hawai‛i; John Bally, University of Colorado; Luca Ricci, California Institute of Technology; A. Meredith Hughes, Wesleyan University, and Brenda C. Matthews, National Research Council of Canada.

Official press release: https://public.nrao.edu/news/pressreleases/death-stars-in-orion

Milky Way amidst a ‘Council of Giants’ (March 11, 2014)

We live in a galaxy known as the Milky Way – a vast conglomeration of 300 billion stars, planets whizzing around them, and clouds of gas and dust floating in between.

Though it has long been known that the Milky Way and its orbiting companion Andromeda are the dominant members of a small group of galaxies, the Local Group, which is about 3 million light years across, much less was known about our immediate neighbourhood in the universe.

Now, a new paper by York University Physics & Astronomy Professor Marshall McCall, published today in the Monthly Notices of the Royal Astronomical Society, maps out bright galaxies within 35-million light years of the Earth, offering up an expanded picture of what lies beyond our doorstep.

“All bright galaxies within 20 million light years, including us, are organized in a ‘Local Sheet’ 34-million light years across and only 1.5-million light years thick,” says McCall. “The Milky Way and Andromeda are encircled by twelve large galaxies arranged in a ring about 24-million light years across – this ‘Council of Giants’ stands in gravitational judgment of the Local Group by restricting its range of influence.”

McCall says twelve of the fourteen giants in the Local Sheet, including the Milky Way and Andromeda, are “spiral galaxies” which have highly flattened disks in which stars are forming. The remaining two are more puffy “elliptical galaxies”, whose stellar bulks were laid down long ago. Intriguingly, the two ellipticals sit on opposite sides of the Council. Winds expelled in the earliest phases of their development might have shepherded gas towards the Local Group, thereby helping to build the disks of the Milky Way and Andromeda.

McCall also examined how galaxies in the Council are spinning. He comments: “Thinking of a galaxy as a screw in a piece of wood, the direction of spin can be described as the direction the screw would move (in or out) if it were turned the same way as the galaxy rotates. Unexpectedly, the spin directions of Council giants are arranged around a small circle on the sky. This unusual alignment might have been set up by gravitational torques imposed by the Milky Way and Andromeda when the universe was smaller.”

The boundary defined by the Council has led to insights about the conditions which led to the formation of the Milky Way. Most important, only a very small enhancement in the density of matter in the universe appears to have been required to produce the Local Group. To arrive at such an orderly arrangement as the Local Sheet and its Council, it seems that nearby galaxies must have developed within a pre-existing sheet-like foundation comprised primarily of dark matter.

“Recent surveys of the more distant universe have revealed that galaxies lie in sheets and filaments with large regions of empty space called voids in between,” says McCall. “The geometry is like that of a sponge. What the new map reveals is that structure akin to that seen on large scales extends down to the smallest.”

Original Press Release from the Royal Astronomical Society, on behalf of York University, Toronto, Canada (RAS PR 14/16)

Media Contacts

Robin Heron
Media Relations
York University
Canada
Tel: +1 416 736 2100 x22097
rheron@yorku.ca

Robert Massey
Royal Astronomical Society
Tel: +44 (0)20 7734 3307 x214
Mob: +44 (0)794 124 8035
rm@ras.org.uk

Images and animations

Image 1: https://www.ras.org.uk/images/stories/press/Local%20sheet%20topview.jpg
A diagram showing the brightest galaxies within 20 million light years of the Milky Way, as seen from above. The largest galaxies, here shown in yellow at different points around the dotted line, make up the ‘Council of Giants’. Credit: Marshall McCall / York University

Image 2: https://www.ras.org.uk/images/stories/press/Local%20sheet%20sideview.jpg
A diagram showing the brightest galaxies within 20 million light years of the Milky Way, this time viewed from the side. Credit: Marshall McCall / York University

Movie with sound: http://youtube/VzL7xGzfNlU (channel YorkU Astronomer)
An animation that illustrates the positions of the nearby galaxies, including those in the ‘Council of Giants’, in three dimensions. Credit: Marshall McCall / York University

Movie with no sound: https://www.ras.org.uk/images/stories/press/council_of_giants_nosound_v2.mp4
An animation that illustrates the positions of the nearby galaxies, including those in the ‘Council of Giants’, in three dimensions. Credit: Marshall McCall / York University

Further information

The new work appears in “A Council of Giants”, M. L. McCall, Monthly Notices of the Royal Astronomical Society, Oxford University Press, in press. A copy of the paper is available from http://mnras.oxfordjournals.org/lookup/doi/10.1093/mnras/stu199

Phosphorus in the Young Supernova Remnant Cassiopeia A

An international team of astronomers, including Prof. Dae-Sik Moon at the University of Toronto, has measured for the first time the abundance of phosphorus created in a supernova explosion.

The team’s observational results show that phosphorus is 100 times more abundant in the remains left over from a supernova than elsewhere in the galaxy, confirming that massive exploding stars are the crucibles in which the element is created.

Astronomers have measured the abundance of carbon, nitrogen, oxygen, and sulphur in supernovae remnants before. But this is the first measurement of the relatively scarce phosphorus.

“These five elements are essential to life and can only be created in massive stars,” says Moon, co-author of the paper being published in the journal Science on December 13, 2013.

“They are scattered throughout our galaxy when the star explodes, and they become part of other stars, planets and ultimately, humans,” says Moon. “This is why Carl Sagan said we are made of ‘starstuff’. Now we have measured how much of this particular element of starstuff is created in supernovae.”

Moon is in the Department of Astronomy & Astrophysics and the Dunlap Institute for Astronomy & Astrophysics at the U of T. Other members of the research team include lead author Bon-Chul Koo, Yong Hyun Lee and Sung-Chul Yoon of Seoul National University in Korea, and John Raymond of the Harvard-Smithsonian Center for Astrophysics.

The observations were of the remnant of a supernova believed to have been observed over 300 years ago. Called Cassiopeia A (Cas A), it lies at a distance of about 11,000 light-years.

Astronomers believe the original star was between 15 and 25 times the mass of the Sun. When a star of such mass runs out of the hydrogen that it burns to produce energy, the core of the star goes through a sequence of collapses, synthesizing heavier elements with each collapse.

Moon and his colleagues made their observations using the TripleSpec near-infrared spectrograph on the Palomar 5-metre Hale telescope. The instrument—which Moon co-developed—allowed the team to directly compare the spectral lines of phosphorus and iron and, thus, calculate the abundance ratio of the two.

Carl Sagan knew that this starstuff is the “…the calcium in our teeth, the iron in our blood.” Now, Moon and his colleagues have directly measured the starstuff that is the phosphorus in our DNA and our bones.

CONTACT INFORMATION:

Prof. Dae-Sik Moon
Department of Astronomy & Astrophysics
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
e: moon@astro.utoronto.ca
p: 416-978-6566
http://www.astro.utoronto.ca/~moon

Chris Sasaki
Public Information Officer
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
e: csasaki@dunlap.utoronto.ca
p: 416-978-6613

The Dunlap Institute for Astronomy & Astrophysics, University of Toronto, continues the legacy of the David Dunlap Observatory: by developing innovative astronomical instrumentation, including for the largest, most advanced telescopes in the world; by training the next generation of astronomers; and by fostering public engagement in science. The research of its faculty and postdoctoral fellows includes the discovery of exoplanets, the formation of stars, galactic nuclei, the evolution and nature of galaxies, the early Universe and the Cosmic Microwave Background, and the Search for Extra-terrestrial Intelligence (SETI).

Special Instructions: For image for splash page, visit http://dunlap.utoronto.ca/for-the-media/downloads/ Password: CasA

Dunlap Award for Innovation in Astronomical Research Tools (October 30, 2013)

The Canadian Astronomical Society is pleased to announce the establishment of a new Award, the Dunlap Award for Innovation in Astronomical Research Tools.

The Dunlap Award is made possible thanks to a generous gift from the Dunlap Institute for Astronomy & Astrophysics, University of Toronto.

The award will be presented in even-numbered years to an individual or team for the design, invention, or improvement of instrumentation or software that has enabled significant advances in astronomy. The nominee, or leader of a nominated team, shall be a member of CASCA and a Canadian astronomer or an astronomer working in Canada.

Nominations for the 2014 Dunlap Award are sollicited at this time and can be tended until 15 January 2015. Details can be found on the Dunlap Award page on the CASCA website: https://casca.ca/?page_id=2724.

In June 2014, CASCA will present the inaugural Dunlap Award at the society’s annual meeting in Quebec City.

 
Contacts:
 
Leslie Sage
CASCA press officer
cascapressofficer@gmail.com
+1 301 675 8957

Chris Sasaki
Communications and New Media Specialist
Dunlap Institute for Astronomy & Astrophysics
University of Toronto
50 St. George Street
Toronto, Canada
M5S 3H4
csasaki@dunlap.utoronto.ca
416 978 6613

Scientific Authorities Sign the TMT Master Agreement (July 25, 2013)

The Thirty Meter Telescope (TMT) project announces today that all of the scientific authorities of the TMT partners have signed a Master Agreement. The Master Agreement document establishes a formal agreement amongst the international parties defining the project goals, establishing a governance structure and defining member party rights, obligations and benefits.

TMT is a unique and vibrant collaboration among universities in the United States with institutions in the nations of Canada, China, India and Japan, and with major funding from the Gordon and Betty Moore Foundation. Uniting these various parties under a Master Agreement stands as a significant accomplishment for TMT as a scientific endeavor with global reach.

“The signing of this Master Agreement marks a major milestone in the official commitment to and formalization of this global collaboration, ensuring that the TMT project is on schedule and progressing smoothly,” said Henry Yang, Chair of the TMT Collaborative Board. “We have been working towards this moment for a long time and this is a special day for astronomy’s next-generation observatory.”

The Master Agreement brings together the TMT partners for the purpose of developing, designing, financing, constructing, commissioning, operating and decommissioning a next-generation, thirty meter-class astronomical observatory.

“We are pleased with this vote of confidence from the scientific authorities,” said Edward Stone, Vice Chair of the TMT Board. “Their signing of this Master Agreement is a key endorsement of TMT’s scientific merits as well as the project’s overall implementation plan.”

Looking ahead, the next step will be for the financial authorities of the partners to similarly sign the document and finalize the funding plan.

“With the scientific authorities now all on board, we welcome and look forward to the critical support of the remaining financial authorities in advancing the TMT project,” said Yang.

2013 has been a busy and successful year for TMT, and the signing of the Master Agreement is a major step forward in the creation of a revolutionary astronomical facility. Construction of TMT is planned to begin in April 2014 and TMT is scheduled to begin scientific operations in 2022 on Mauna Kea, Hawaii.

Signatories of the Master Agreement:

The signatories of the Master Agreement are: Donald E. Brooks, Chair of the Association of Canadian Universities for Research in Astronomy (ACURA) Institutional Council; Jean-Lou Chameau, President of the California Institute of Technology; Masahiko Hayashi, Director General of the National Astronomical Observatory of Japan (NAOJ); Dr. P. Sreekumar, Director of the Indian Institute of Astrophysics; Jun Yan, Director General of the National Astronomical Observatories of China (NAOC) and Mark Yudof, President of the University of California.

Statements from TMT Partners:

“ACURA is pleased to be a partner in signing the Master Agreement as Scientific Authority, and is currently engaged with the National Research Council to discuss moving the project forward for funding in Canada. TMT will be a vital resource for research in Canadian universities. It will deepen our knowledge of many of the major issues in astronomy & astrophysics in ways that would not be possible without such a new generation telescope,” said Ernie Seaquist, Executive Director of the Association of Canadian Universities for Research in Astronomy (ACURA).

“China is excited to be an active partner of such a world-leading facility, which represents a quantum leap for our community. With yet another major step taken, we look forward to many decades of solving the mysteries of the cosmos from Mauna Kea,” said Jun Yan, Director General of the National Astronomical Observatories of China.

”We are delighted to start contribution to make this scientific enterprise a reality. We believe TMT and Subaru will be a good match to explore many key riddles of the Universe,” said Prof. Masahiko Hayashi, the Director General of the National Astronomical Observatory of Japan.

“TMT-India is extremely happy to participate in the joint signing of the TMT Master Agreement. It is an important milestone in our global endeavor to raise astronomical observations to a new level with the promise of exciting science. With a large number of young students and researchers in our growing academic program, the Indian astronomical community sees the complete realization of the TMT project as an important stimulus to astrophysics research programs in India. We look forward to jointly addressing the next milestone in this program,” said Dr. P. Sreekumar, Director, Indian Institute of Astrophysics.

About the Gordon and Betty Moore Foundation:

The Gordon and Betty Moore Foundation believes in bold ideas that create enduring impact in the areas of science, environmental conservation and patient care. Intel co-founder Gordon and his wife Betty established the foundation to create positive change around the world and at home in the San Francisco Bay Area. Science looks for opportunities to transform–or even create–entire fields by investing in early-stage research, emerging fields and top research scientists. Environmental conservation efforts promote sustainability, protect critical ecological systems and align conservation needs with human development. Patient care focuses on eliminating preventable harms and unnecessary healthcare costs through meaningful engagement of patients and their families in a supportive, redesigned healthcare system. Visit us at Moore.org or follow @MooreScientific.

About TMT:

TMT is the next-generation astronomical observatory that is scheduled to begin scientific operations in 2022 on Mauna Kea, Hawaii. TMT is a collaboration of the California Institute of Technology, University of California, the Association of Canadian Universities for Research in Astronomy, the National Astronomical Observatory of Japan, a consortium of Chinese institutions led by the National Astronomical Observatories of the Chinese Academy of Sciences, and institutions in India supported by the Department of Science and Technology of India. Major funding has been provided by the Gordon & Betty Moore Foundation. For more information, visit tmt.org , www.facebook.com/TMTHawaii or follow @TMTHawaii.

TMT Media contact:

Gordon K. Squires
TMT Communications & Outreach Lead
squires@tmt.org
626-216-4257

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: