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Astronomers peer through cosmic dust to see origins of the Universe
Astronomers using the James Clerk Maxwell Telescope (JCMT) in Hawaii are set to make major new discoveries about the origins of the planets, stars and galaxies with the start of a new survey to map the Universe.
The JCMT Legacy Survey, made up of 7 projects, makes use of two sophisticated new instruments - SCUBA-2 and HARP – which will allow the astronomers to detect and probe clouds of cold dust associated with the mysterious earliest phases of the formation of galaxies, stars and planets.
SCUBA-2 is a powerful camera capable of mapping regions of the sky by detecting the heat emitted by this extremely cold dust. It has recently been delivered to the JCMT and is under commission. When completed it will have the ability to pinpoint and image many hundreds of distant, dust enshrouded galaxies in a single night. Many of these galaxies are among the earliest structures observable in the universe and are largely undetectable by other telescopes. The Harp instrument allows astronomers to see the motion of this gas with clarity and precision and has the powerful ability to record information in three dimensions.
The UK’s Science and Technology Facilities Council (STFC) jointly owns and operates the JCMT and much of the design and construction of the telescope and the existing and future instrumentation, including SCUBA-2 and HARP, has been undertaken by groups in the UK, in particular STFC’s UK Astronomy and Technology Centre and the Universities of Wales, Cardiff and Edinburgh.
Projects already underway include the Nearby Galaxies Legacy Survey, the Gould Belt Survey and the Spectral Legacy Survey. All 3 of these projects use the HARP instrument.
The Nearby Galaxies Legacy Survey aims to produce the first large sample of galaxies close to our own (within 81,500,000 light years). The data will help us to better understand the properties of the matter that exists between the stars in these galaxies, how it is affected by its environment, and how it compares with our Galaxy.
Professor Christine Wilson from McMaster University, Canada, who leads the project, said: "It has been very exciting over the last year to go from verifying the performance of HARP/ACSIS on the JCMT to completing over 80% of our HARP survey. We have been kept very busy processing the flood of data that is being produced, but the reward has been seeing all these beautiful images of nearby galaxies appearing one by one. It simply would not have been possible to obtain so many large and sensitive images of our galactic neighbours without HARP/ACSIS. We are using these new data from the Nearby Galaxy Legacy Survey to map out how the dense gas, which is the fuel for forming new stars, is distributed in galaxies with different masses and environments. One of our exciting results is to be able to map, for the first time, how efficiently gas is being turned into stars from one region of a galaxy to another."
Closer to home, a complete survey of star formation within 1,630 light years of our Sun is the aim of the Gould Belt Survey (so-called for the belt of star forming clouds encircling our Sun), a project led by Dr Jennifer Hatchell at the University of Exeter. The JCMT and its instruments are well suited for studies of star formation as it is only at these long wavelengths that we are able to probe into the coldest, densest regions of clouds where stars are actively forming.
Dr Hatchell says: "The maps coming out of HARP are larger and better quality than anything we had to work with before. Now we can see just how much the gas clouds are being moved about by the newly-forming stars inside them."
The sensitive observations that the JCMT can provide will give astronomers a better understanding of the processes required to form stars and a clearer idea of how often and efficiently this happens.
Professor Derek Ward-Thompson from Cardiff University said: "These HARP images allow us to see a three-dimensional picture of star birth in molecular clouds. It shows just what a violent process star birth is - in fact almost as violent as a star's death."
The details of the star formation process are to be provided by the Spectral Legacy Survey. This survey team will obtain a chemical inventory of star formation in a sample carefully selected to span different evolutionary stages of development.
Dr John Richer from Cambridge University said: "We've never made images like these before. With previous instruments, the maps would have taken too long to make - several weeks or so. But in only eight hours of observing, HARP has generated incredible new images which for the first time reveal the fine details of star formation."
"We have been preparing for the JCMT Legacy Survey for several years", says Professor Gary Davis, the Director of the JCMT. "This is the culmination of a process in which astronomers in the UK, Canada and the Netherlands came together to define a unified and comprehensive survey of the submillimetre sky. This has never been done before because the revolutionary instruments required to do it have not, until now, been available. The survey programme is of the highest scientific calibre and will have far-reaching effects on all areas of astrophysics. The spectacular results so far are just a tantalising hint of what is yet to come."
The JCMT Legacy Survey is also actively being used by the teams of researchers as a fertile training ground for future astronomers.
Robert Simpson, a PhD student from Cardiff University, UK, says: "The images produced by HARP have smashed my old notions of the beautiful and serene nebula. As a kid I always thought nebulae were so gentle and elegant, but images such as these reveal the violence and energy flowing inside them. I've seen the equations and I've read the theory, but these images show you the physics behind star formation in a better, more intuitive way. Working on HARP data during my PhD has given me a new insight into star formation and has changed my perspective. What more can you ask for from science?"
Notes for Editors
Contacts
Inge Heyer, Science Outreach Specialist
Joint Astronomy Centre
Tel: +1 808-969-6524
Fax: +1 808-961-6516
Email: outreach@jach.hawaii.edu
Julia Short
STFC Press Office
Tel: +44 (0)1793 442 012
Email: julia.short@stfc.ac.uk
Science Contacts
Please note that it is best to contact these individuals by email.
• Dr Jennifer Hatchell (GBS Team)
University of Exeter, UK
Desk: +44 1392-725516
Email: hatchell@astro.ex.ac.uk
• Prof. Christine Wilson (NGLS Team)
McMaster University, Canada
Desk: +1 905-525-9140 (x27483)
Email: wilson@physics.mcmaster.ca
• Dr Floris van der Tak (SLS Team)
SRON, Netherlands
Desk: +31 50-363-8753
Email: vdtak@sron.rug.nl
• Dr Antonio Chrysostomou
Joint Astronomy Centre
Desk: +1 808-969-6512
Email: a.chrysostomou@jach.hawaii.edu
• Prof. Gary Davis
Joint Astronomy Centre
Desk: +1 808-969-6504
Email: g.davis@jach.hawaii.edu
Images
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/NGC3627_int_olay_dss_colour.jpg (JPG image, 1.63 MB) This image from the JCMT Nearby Galaxies Legacy Survey shows the integrated carbon-monoxide (12CO) J=3-2 intensity for NGC 3627 (M66) as contours overlaid on an optical image from the Digitized Sky Survey. NGC 3627 is an asymmetric barred spiral galaxy that is well known for its high star formation activity and prominent spiral arms. It is a member of the Leo Triplet of galaxies at a distance of 29 million light years which is well known for its unusual kinematics that are influenced by both its bar and external interactions. Our map shows strong CO 3-2 emission in the central bar and along the spiral arms of the galaxy, with particularly strong emission in the centre and at the ends of the bar. The lopsided structure is similar to past studies at other CO transitions.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/NGC3627_velfield_colour.jpg (JPG image, 332 KB) This image shows the doppler-shifted velocity field for NGC 3627 (M66) measured using the 12CO J=3-2 emission line.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/NGC4321_int_olay_dss_colour.jpg (JPG image, 1.51 MB) This image from the JCMT Nearby Galaxies Legacy Survey shows the integrated carbon-monoxide (12CO) J=3-2 intensity for M100 (NGC 4321) as contours overlaid on an optical image from the Digitized Sky Survey. M100 is a nearly face-on grand design spiral galaxy and a member of the Virgo cluster, which lies at a distance of 54 million light years and is the nearest rich cluster of galaxies. Our map shows strong CO 3-2 emission in the centre bulge, with weaker emission in the spiral arms that roughly trace apparent star formation sites.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/NGC4321_velfield_colour.jpg (JPG image, 449 KB) This image from the JCMT Nearby Galaxies Legacy Survey shows the doppler-shifted velocity field for M100 (NGC 4321) measured using the 12CO J=3-2 emission line. The image shows a very typical velocity field for spiral galaxies of this type, with a steep gradient in the centre of the galaxy and smooth rotation in the outer parts.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_12co_rgb.jpg (image, 170 KB) http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_12co_rgb.png (PNG image, 251 KB Emission of the carbon-monoxide molecule (12CO) from the centre of the Serpens star forming cloud, imaged with HARP during the Gould Belt Survey. The relative motion of the gas is colour coded, with blue showing gas moving at 10 km/s toward us, green showing nearly stationary gas, and red showing gas moving away from us at 10 km/s. These data dramatically show a burst of supersonic jets of gas from this cluster of new-born stars. These jets may be ripping apart part the very cloud from which the stars have formed. The HARP data show how dynamic star birth really is. In this panel (as well as all other ones) the depicted region measures approximately 1.0 by 1.5 light years. See inset figure for orientation of the field.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_13co_rgb.jpg (JPG image, 285 KB) http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_13co_rgb.png (PNG image, 373 KB Emission from 13CO, the carbon-monoxide molecule substituted with the heavy isotope 13C, with red showing gas moving at 4 km/s away from us, and blue showing gas moving at 4 km/s towards us.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_c18o_rgb.jpg (JPG image, 368 KB) http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_c18o_rgb.png (PNG image, 460 KB) Emission from C18O, the carbon-monoxide molecule substituted with the heavy isotope 18O, with red showing gas moving at a few tenths of a km/s away from us, and blue showing gas moving at a few tenths of a km/s towards us. Compare these small velocity shifts with the 10 km/s shifts measured in 12CO. Only 1 in 500 carbon-monoxide molecules carries the 18O atom, allowing us to view much deeper into the cloud and uncover the overall rotation of the cloud (roughly east-west) as well as the subtle effect that the jets seen in regular carbon-monoxide (12CO) may have on the structure and turbulence of the cloud material.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_12co_sources.jpg (JPG image, 70 KB) http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/serpens_12co_sources.png (PNG image, 59 KB) Crosses mark the location of the known newly formed stars, superposed on the map of the carbon-monoxide emission. The compass shows the orientation of the imaged field
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/orion_composite.jpg (JPG image, 303 KB) http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/orion_composite.eps (EPS image, 30 KB The three panels from the Spectral Legacy Survey show the colour scale and contours of the emission from three different molecules (sulphur monoxide, formaldehyde and a hydrocarbon chain (C2H)) towards the Orion Bar, a region which is being illuminated by a strong ultraviolet radiation field produced by nearby young stars. The asterisks are reference points that mark the same sky position in each image. Moving from the left panel to the right panel, the emission from the different molecules moves towards the upper right of the region, showing that these molecules are clearly present in different layers within the gas. This means that we can choose particular molecules to learn how the physical conditions in the gas (such as density, temperature, and chemical composition) change from one region of the cloud to the next. It is precisely this kind of information that is needed to study the earliest phases of star birth and thus, to help us understand the complex process of star formation.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/jcmt.jpg (JPG image, 2.3 MB) The James Clerk Maxwell Telescope on Mauna Kea, Hawaii.
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/acsis_front_sm.jpg (JPG image, 378 KB) http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/acsis_front.jpg (JPG image, 1.8 MB ACSIS being tested in the lab in Canada
http://outreach.jach.hawaii.edu/pressroom/2008_legacysurvey1/harp2.gif (JPG image, 1.8 MB) HARP on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii.
The JCMT is operated by the Joint Astronomy Centre (JAC) on behalf of the UK’s Science and Technology Facilities Council, the National Research Council Canada, and the Netherlands Organisation for Scientific Research. The development of SCUBA 2 is a collaboration between the UK ATC, the USA National Institute of Standards and Technology (NIST), the Astronomy Instrumentation Group at the University of Wales at Cardiff, the Scottish Microelectronics Centre at the University of Edinburgh, a consortium of Canadian Universities and the Joint Astronomy Centre (JAC). Design and construction of the camera is led by UK ATC in collaboration with the Universities of Wales, Cardiff and Edinburgh. The HARP project is a collaboration between the UK ATC, Cavendish Astrophysics (MRAO) at the University of Cambridge UK, The Joint Astronomy Centre (JAC) at Hilo in Hawaii (operators of the JCMT) and The Herzberg Institute of Astrophysics (HIA) of the National Research Council Canada. The UK ATC is also involved in writing the software for a new Observatory Control System for the JCMT that will allow astronomers to pre-programme their observations using HARP and the other JCMT instruments. Science and Technology Facilities Council The Science and Technology Facilities Council ensures the UK retains its leading place on the world stage by delivering world-class science; accessing and hosting international facilities; developing innovative technologies; and increasing the socio-economic impact of its research through effective knowledge exchange partnerships. The Council has a broad science portfolio including Astronomy, Particle Physics, Particle Astrophysics, Nuclear Physics, Space Science, Synchrotron Radiation, Neutron Sources and High Power Lasers. In addition the Council manages and operates three internationally renowned laboratories: • The Rutherford Appleton Laboratory, Oxfordshire • The Daresbury Laboratory, Cheshire • The UK Astronomy Technology Centre, Edinburgh The Council gives researchers access to world-class facilities and funds the UK membership of international bodies such as the European Laboratory for Particle Physics (CERN), the Institute Laue Langevin (ILL), European Synchrotron Radiation Facility (ESRF), the European organisation for Astronomical Research in the Southern Hemisphere (ESO) and the European Space Agency (ESA). It also contributes money for the UK telescopes overseas on La Palma, Hawaii, Australia and in Chile, and the MERLIN/VLBI National Facility, which includes the Lovell Telescope at Jodrell Bank Observatory. The Council distributes public money from the Government to support scientific research. Between 2008 and 2009 we will invest approximately £787 million. The Council is a partner in the UK space programme, coordinated by the British National Space Centre. UK Astronomy Technology Centre The UK Astronomy Technology Centre is the national centre for astronomical technology. They design and build instruments for many of the world’s major telescopes and project-manage UK and international collaborations. Their scientists carry out observational and theoretical research into fundamental questions such as the origins of planets and of galaxies.
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