The Royal Astronomical Society expects to issue a number of press releases on the exciting research presented at the meeting. Embargoed copies will be made available to journalists several days in advance, to aid them in preparing their stories.
At the conference venue, a press room will be available for journalists to work in, along with a suitable space for interviews. RAS press office staff will be on hand to assist journalists e.g. in finding suitable scientists to comment on stories.
If you wish to take advantage of any of these services, or are interested in media coverage of the event, please contact This email address is being protected from spambots. You need JavaScript enabled to view it.
ALMA discovers dew drops surrounding dusty spider’s web
Annotated image of the Spiderweb Galaxy, as seen by the Hubble Space Telescope (optical) in red, the Very Large Array (radio) in green and the Atacama Large Millimeter/submillimeter Array (sub-millimetre) in blue. The red colour shows where the stars are located within this system of galaxies. The radio jet is shown in green, and the position of the dust and water are seen in blue. The water is located to the left and right of the central galaxy. The water to the right is at the position where the radio jet bends down wards. The dust is also seen in blue. The dust is located at the central galaxy and in smaller companion galaxies in its surroundings. Credit: NASA/ESA/HST/STScI/NRAO/ESO/Astronomers have spotted glowing droplets of condensed water in the distant Spiderweb Galaxy – but not where they expected to find them. Detections with the Atacama Large Millimeter/submillimeter Array (ALMA) show that the water is located far out in the galaxy and therefore cannot be associated with central, dusty, star-forming regions, as previously thought. The results will be presented at the National Astronomy Meeting 2016 in Nottingham by Dr Bitten Gullberg on Friday 1st July.
“Observations of light emitted by water and by dust often go hand-in-hand. We usually interpret them as an insight into star-forming regions, with the illumination from young stars warming dust particles and water molecules until they start to glow. Now, thanks to the power of ALMA, we can -- for the first time -- separate out the emissions from the dust and water populations, and pinpoint their exact origins in the galaxy. The results are quite unexpected in that we’ve found that the water is located nowhere near the dusty stellar nurseries,” explained Dr Gullberg, of the Centre for Extragalactic Astronomy, Durham University, UK.
The Spiderweb Galaxy is one of the most massive galaxies known. It lies 10 billion light-years away and is made up of dozens of star-forming galaxies in the process of merging together. The ALMA observations show that the light from the dust originates in the Spiderweb Galaxy itself. However, the light from the water is concentrated in two regions far to the east and west of the galaxy core.
Gullberg and her colleagues believe that the explanation lies with powerful jets of radio waves that are ejected from a supermassive black hole at the centre of the Spiderweb Galaxy. The radio jets compress clouds of gas along their path and heat up water molecules contained within the clouds until they emit radiation.
“Our results show how important it is to pinpoint the exact locations and origins for light in galaxies. We may also have new clues to the processes that trigger star formation in interstellar clouds,” said Gullberg. “Stars are born out of cold, dense molecular gas. The regions in the Spiderweb where we’ve detected water are currently too hot for stars to form. But the interaction with the radio jets changes the composition of the gas clouds. When the molecules have cooled down again, it will be possible for the seeds of new stars to form. These “dew drop” regions could become the next stellar nurseries in this massive, complex galaxy.”
Media contacts
Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877 699
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Ms Anita Heward
Royal Astronomical Society
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Science contacts
Dr Bitten Gullberg
Centre for Extragalactic Astronomy
Durham University
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Images
The Spiderweb Galaxy as seen by the Hubble Space Telescope (optical) in red, the Very Large Array (radio) in green and the Atacama Large Millimeter/submillimeter Array (sub-millimetre) in blue. The red colour shows where the stars are located within this system of galaxies. The radio jet is shown in green, and the position of the dust and water are seen in blue. The water is located to the left and right of the central galaxy. The water to the right is at the position where the radio jet bends down wards. The dust is also seen in blue. The dust is located at the central galaxy and in smaller companion galaxies in its surroundings. Credit: NASA/ESA/HST/STScI/NRAO/ESO/
Annotated image: http://nam2016.org/images/nam2016/Media/Gullberg/Spider.jpg
Unannotated image: http://nam2016.org/images/nam2016/Media/Gullberg/Spider2.jpg
Further information
ALMA Finds Dew Drops in the Dusty Spider’s Web, Bitten Gullberg et al, February 2016, Astronomy & Astrophysics: http://arxiv.org/pdf/1602.04823v1.pdf
Notes for editors
The RAS National Astronomy Meeting 2016 (NAM 2016, http://nam2016.org) takes place this year at the University of Nottingham from 27 June to 1 July. NAM 2016 brings together more than 500 space scientists and astronomers to discuss the latest research in their respective fields. The conference is principally sponsored by the Royal Astronomical Society, the Science and Technology Facilities Council and the University of Nottingham. Follow the conference on Twitter via @rasnam2016
The University of Nottingham (http://nottingham.ac.uk/) has 43,000 students and is ‘the nearest Britain has to a truly global university, with a “distinct” approach to internationalisation, which rests on those full-scale campuses in China and Malaysia, as well as a large presence in its home city.’ (Times Good University Guide 2016). It is also one of the most popular universities in the UK among graduate employers and the winner of ‘Outstanding Support for Early Career Researchers’ at the Times Higher Education Awards 2015. It is ranked in the world’s top 75 by the QS World University Rankings 2015/16, and 8th in the UK by research power according to the Research Excellence Framework 2014. It has been voted the world’s greenest campus for four years running, according to Greenmetrics Ranking of World Universities.
Impact: The Nottingham Campaign, its biggest-ever fundraising campaign, is delivering the University’s vision to change lives, tackle global issues and shape the future.
The Science and Technology Facilities Council (STFC, http://www.stfc.ac.uk) is keeping the UK at the forefront of international science and has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. STFC's Astronomy and Space Science programme provides support for a wide range of facilities, research groups and individuals in order to investigate some of the highest priority questions in astrophysics, cosmology and solar system science. STFC's astronomy and space science programme is delivered through grant funding for research activities, and also through support of technical activities at STFC's UK Astronomy Technology Centre and RAL Space at the Rutherford Appleton Laboratory. STFC also supports UK astronomy through the international European Southern Observatory. Follow STFC on Twitter via @stfc_matters
The Royal Astronomical Society (RAS, http://www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.
Follow the RAS on Twitter via @royalastrosoc
About Durham University
- A world top 100 university with a global reputation and performance in research and education
- Ranked 61 globally in the QS World University Rankings 2015/16
- Ranked 31 globally for the employability of its students by blue-chip companies world-wide (QS World University Rankings 2015/16)
- Ranked 70 globally in the THE World University Rankings 2015/16
- In the global top 50 for Arts and Humanities (THE World University Rankings 2014/15)
- A member of the Russell Group of leading research-intensive UK universities
- Research at Durham shapes local, national and international agendas, and directly informs the teaching of our students
- In the 2016 Times and Sunday Times Good University Guide and the 2016 Complete University Guide, Durham was ranked fifth in the UK.
- Durham was named as The Times and Sunday Times 'Sports University of the Year 2015' in recognition of outstanding performance in both the research and teaching of sport, and student and community participation in sport at all levels.
Gravitational lens zooms in on why some quasars have the radio turned down
Left: Reconstruction of the lensed radio-quiet quasar HS0810+2554 after removing the effects of the lensing. Right: the data from the Karl G. Jansky Very Large Array showing what the source looks like after passage through the lensing galaxy. The images are not to scale - the lensed image appears to be many times larger in the sky than the actual size of the source. N Jackson/NRAOMini-jets of material ejected from a central supermassive black hole appear to be the culprits behind faint radio wave emissions in ‘radio-quiet’ quasars. A study of gravitationally-lensed images of four radio-quiet quasars has revealed the structure of these distant galaxies in unprecedented detail. This has enabled astronomers to trace the radio emissions to a very small region at the heart of the quasars, and helped to solve a 50-year-old puzzle about their source. The results will be presented by Dr Neal Jackson at the National Astronomy Meeting in Nottingham on Friday, 1st July.
“In radio-loud quasars, the intense radio emission clearly comes from vast jets of material blasted out from the region around a central black hole. By contrast, the radio emission from radio-quiet quasars is extremely feeble and difficult to see, so it has been hard to identify its source,” explained Jackson of the Jodrell Bank Centre for Astrophysics in Manchester. “To study most radio-quiet quasars, we will have to wait until future extremely large telescopes, like the Square Kilometre Array, come online. However, if we find radio-quiet quasars which are lensed by galaxies in front of them, we can use the increased brightness to be able to study them with today's radio telescopes.”
Gravitational lensing is a phenomenon where light from distant objects is warped by the gravitational field of massive objects in the foreground, a bit like light travelling through a glass lens. The mass distribution in a galaxy acts rather like a lens shaped like the bottom of a wineglass, and produces multiple images of background objects, with images stretched out into arcs and rings.
Jackson and colleagues used the Karl G. Jansky Very Large Array, in New Mexico, US, to study four examples of gravitational lens systems where the background quasar appears in a ring of four, distorted images. Two of the systems were also observed by the UK’s e-MERLIN array. After correcting for the distorting effects of the lens, the team were able to accurately measure the sizes of the radio-emitting regions in the sample of quasars.
“The cause of radio emissions in radio-quiet quasars has been the subject of debate. One theory suggested that they were caused by multiple explosions of individual supernovae in the galaxy surrounding the quasar,” said Jackson. “These new observations have allowed us to narrow down the emissions to a very small region, typical of an active nucleus – i.e. jets emanating from a supermassive black hole. We are currently working on some further data that we hope will confirm our preliminary findings. If so, we can rule out the supernova explanation, which would show radio emissions from a much larger area, and confirm that the processes driving radio-quiet quasars are the same as their loud counterpart, just on a smaller scale.”
Images
1. e-MERLIN picture of one of the lensed radio-quiet quasars, HS0810+2554. Credit: N Jackson/JCBA
https://nam2016.org/images/nam2016/Media/Jackson/0810_merlin2.jpg
2. Left: Reconstruction of the lensed radio-quiet quasar HS0810+2554 after removing the effects of the lensing. Right: the data from the Karl G. Jansky Very Large Array showing what the source looks like after passage through the lensing galaxy. The images are not to scale - the lensed image appears to be many times larger in the sky than the actual size of the source. N Jackson/NRAO
https://nam2016.org/images/nam2016/Media/Jackson/0810_source_lens.jpg
3. A montage of the Karl G. Jansky Very Large Array data for this object (greyscale) with Hubble Space Telescope data overlaid (contours). N Jackson/NRAO/NASA/ESA
https://nam2016.org/images/nam2016/Media/Jackson/fig_0810_new.png
Media contacts
Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877 699
This email address is being protected from spambots. You need JavaScript enabled to view it.
Ms Anita Heward
Royal Astronomical Society
Mob: +44 (0)7756 034 243
This email address is being protected from spambots. You need JavaScript enabled to view it.
NAM 2016 press office
Tel: +44 (0)115 8466993
An ISDN line and a Globelynx fixed camera are available for radio and TV interviews. To request these, please contact Robert or Anita.
Science contacts
Dr Neal Jackson
Jodrell Bank Centre for Astrophysics
The School of Physics and Astronomy
The University of Manchester
This email address is being protected from spambots. You need JavaScript enabled to view it.
Notes to editors
The RAS National Astronomy Meeting 2016 (NAM 2016, http://nam2016.org) takes place this year at the University of Nottingham from 27 June to 1 July. NAM 2016 brings together more than 550 space scientists and astronomers to discuss the latest research in their respective fields. The conference is principally sponsored by the Royal Astronomical Society and the Science and Technology Facilities Council. Follow the conference on Twitter via @rasnam2016
The University of Nottingham (http://nottingham.ac.uk/) has 43,000 students and is ‘the nearest Britain has to a truly global university, with a “distinct” approach to internationalisation, which rests on those full-scale campuses in China and Malaysia, as well as a large presence in its home city.’ (Times Good University Guide 2016). It is also one of the most popular universities in the UK among graduate employers and the winner of ‘Outstanding Support for Early Career Researchers’ at the Times Higher Education Awards 2015. It is ranked in the world’s top 75 by the QS World University Rankings 2015/16, and 8th in the UK by research power according to the Research Excellence Framework 2014. It has been voted the world’s greenest campus for four years running, according to Greenmetrics Ranking of World Universities.
Impact: The Nottingham Campaign, its biggest-ever fundraising campaign, is delivering the University’s vision to change lives, tackle global issues and shape the future.
The Science and Technology Facilities Council (STFC, http://www.stfc.ac.uk) is keeping the UK at the forefront of international science and has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. STFC's Astronomy and Space Science programme provides support for a wide range of facilities, research groups and individuals in order to investigate some of the highest priority questions in astrophysics, cosmology and solar system science. STFC's astronomy and space science programme is delivered through grant funding for research activities, and also through support of technical activities at STFC's UK Astronomy Technology Centre and RAL Space at the Rutherford Appleton Laboratory. STFC also supports UK astronomy through the international European Southern Observatory. Follow STFC on Twitter via @stfc_matters
The Royal Astronomical Society (RAS, http://www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.
Follow the RAS on Twitter via @royalastrosoc
It’s not easy being green – what colours tell us about galaxy evolution
Scientists may have answered why green galaxies are rare in our universe and why their colour could reveal a troubled past. Their research is presented today (Thursday 30 June) at the National Astronomy Meeting at the University of Nottingham.
The international team, led from Durham University's Institute for Computational Cosmology (ICC), used new computer modelling of the universe to investigate the colours that galaxies have and what those colours might tell us about how galaxies evolve. Using the state of the art EAGLE simulations, the researchers modelled how both the ages of stars in galaxies and what those stars are made from translate into the colour of light that they produce.
Composite image of blue, green and red galaxies: L-R Virtual images of blue, green and red galaxies produced by the EAGLE simulations. The green galaxy is caught in the act of transforming from blue to red as its gas supply runs out. Credit: James Trayford/EAGLE/Durham University. Click for a full size image
The team said their simulations showed that colours of galaxies can also help diagnose how they evolve.
While red and blue galaxies are relatively common, rare green galaxies are likely to be at an important stage in their evolution, when they are rapidly turning from blue – when new stars and planets are being born – to red as stars begin to burn themselves out.
Lead researcher James Trayford, PhD student in the ICC, said: “Galaxies emit a healthy blue glow while new stars and planets are being born. However, if the formation of stars is halted galaxies turn red as stars begin to age and die.
“In the real universe we see many blue and red galaxies, but these intermediate ‘green’ galaxies are more rare.
“This suggests that the few green galaxies we catch are likely to be at a critical stage in their evolution; rapidly turning from blue to red.”
Because stars form from dense gas, a powerful process is needed to rapidly destroy their gas supply and cause such dramatic changes in colour, the research found.
James added: “In a recent study we followed simulated galaxies as they changed colour, and investigated what processes caused them to change.
“We typically find that smaller green galaxies are being violently tossed around by the gravitational pull of a massive neighbour, causing their gas supply to be stripped away.
“Meanwhile, bigger green galaxies may self-destruct as immense explosions triggered by supermassive black holes at their centres can blow dense gas away.”
However, the research found that there was some hope for green galaxies as a lucky few might absorb a fresh supply of gas from their surroundings. This can revive the formation of stars and planets, and restore galaxies to a healthy blue state.
James said: “By using simulations to study how galaxy colours change, we can speed up the process of galaxy evolution from the billions of years it takes in the real Universe to just a matter of days in a computer.
“This means we don’t just see galaxy colours frozen in time, we can watch them evolve. Another advantage is that we can remove unwanted factors that may change the colours we see, such as pesky dust clouds that can prevent light escaping from galaxies.
“As the EAGLE simulations we use represent a new level of realism, we can have greater confidence in applying these results to the real universe.”
Media contacts
Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877 699
This email address is being protected from spambots. You need JavaScript enabled to view it.
Ms Anita Heward
Royal Astronomical Society
Mob: +44 (0)7756 034 243
This email address is being protected from spambots. You need JavaScript enabled to view it.
NAM 2016 press office (from Monday 27 June to Friday 1 July)
Tel: +44 (0)115 846 6993
An ISDN line and a Globelynx fixed camera are available for radio and TV interviews. To request these, please contact Robert or Anita.
Alternatively please contact the Durham University Marketing and Communications Office
Tel: +44 (0)191 334 6075
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Science contact
James Trayford
Institute for Computational Cosmology
Durham University
(Available for interview on Wednesday, June 29 and Thursday, June 30, 2016)
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Images and captions
Composite image of blue, green and red galaxies: L-R Virtual images of blue, green and red galaxies produced by the EAGLE simulations. The green galaxy is caught in the act of transforming from blue to red as its gas supply runs out. Credit: James Trayford/EAGLE/Durham University
Image of blue galaxy from EAGLE simulation. Credit: James Trayford/EAGLE/Durham University
Image of green galaxy from EAGLE simulation. Credit: James Trayford/EAGLE/Durham University
Image of red galaxy from EAGLE simulation: Credit: James Trayford/EAGLE/Durham University
Further information
The research is funded by the Science and Technology Facilities Council (STFC) and the European Research Council (ERC).
It's not easy being green: The evolution of galaxy colour in the EAGLE simulation, Trayford James, W, et al is being presented at the Royal Astronomical Society’s National Astronomy Meeting, at the University of Nottingham, Thursday, June 30, 2016.
The EAGLE simulation project is a flagship of the Virgo consortium, and is led by scientists in Durham, Leiden and Liverpool John Moores Universities. The simulations created by the project were carried out on the DiRAC computing facility in Durham and at the Curie computing facility based in France
Institute for Computational Cosmology
Notes for editors
The RAS National Astronomy Meeting 2016 (NAM 2016) takes place this year at the University of Nottingham from 27 June to 1 July. NAM 2016 brings together more than 550 space scientists and astronomers to discuss the latest research in their respective fields. The conference is principally sponsored by the Royal Astronomical Society and the Science and Technology Facilities Council. Follow the conference on Twitter
About Durham University
- A world top 100 university with a global reputation and performance in research and education
- Ranked 61 globally in the QS World University Rankings 2015/16
- Ranked 31 globally for the employability of its students by blue-chip companies world-wide (QS World University Rankings 2015/16)
- Ranked 70 globally in the THE World University Rankings 2015/16
- In the global top 50 for Arts and Humanities (THE World University Rankings 2014/15)
- A member of the Russell Group of leading research-intensive UK universities
- Research at Durham shapes local, national and international agendas, and directly informs the teaching of our students
- In the 2016 Times and Sunday Times Good University Guide and the 2016 Complete University Guide, Durham was ranked fifth in the UK.
- Durham was named as The Times and Sunday Times 'Sports University of the Year 2015' in recognition of outstanding performance in both the research and teaching of sport, and student and community participation in sport at all levels.
The University of Nottingham has 43,000 students and is ‘the nearest Britain has to a truly global university, with a “distinct” approach to internationalisation, which rests on those full-scale campuses in China and Malaysia, as well as a large presence in its home city.’ (Times Good University Guide 2016). It is also one of the most popular universities in the UK among graduate employers and the winner of ‘Outstanding Support for Early Career Researchers’ at the Times Higher Education Awards 2015. It is ranked in the world’s top 75 by the QS World University Rankings 2015/16, and 8th in the UK by research power according to the Research Excellence Framework 2014. It has been voted the world’s greenest campus for four years running, according to Greenmetrics Ranking of World Universities.
Impact: The Nottingham Campaign, its biggest-ever fundraising campaign, is delivering the University’s vision to change lives, tackle global issues and shape the future.
The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. STFC's Astronomy and Space Science programme provides support for a wide range of facilities, research groups and individuals in order to investigate some of the highest priority questions in astrophysics, cosmology and solar system science. STFC's astronomy and space science programme is delivered through grant funding for research activities, and also through support of technical activities at STFC's UK Astronomy Technology Centre and RAL Space at the Rutherford Appleton Laboratory. STFC also supports UK astronomy through the international European Southern Observatory. Follow STFC on Twitter
The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.
Follow the RAS on Twitter
In the blink of a cosmic eye: chance microlensing events probe galactic cores
Artist's rendering of ULAS J1120+0641, a very distant quasar (an extreme AGN) powered by a black hole with a mass two billion times that of the Sun. Credit: ESO/M. Kornmesser. Click for a full size imageSome galaxies pump out vast amounts of energy from a very small volume of space, typically not much bigger than our own solar system. The cores of these galaxies, so called Active Galactic Nuclei or AGNs, are often hundreds of millions or even billions of light years away, so are difficult to study in any detail. Natural gravitational ‘microlenses’ can provide a way to probe these objects, and now a team of astronomers have seen hints of the extreme AGN brightness changes that hint at their presence. Leading the microlensing work, PhD student Alastair Bruce of the University of Edinburgh presents their work today (Friday 1 July) at the National Astronomy Meeting in Nottingham.
The energy output of an AGN is often equivalent to that of a whole galaxy of stars. This is an output so intense that most astronomers believe only gas falling in towards a supermassive black hole – an object with many millions of times the mass of the Sun - can generate it. As the gas spirals towards the black hole it speeds up and forms a disc, which heats up and releases energy before the gas meets its demise.
Scientists are particularly interested in seeing what happens to the gas as it approaches the black hole. But studying such small objects at such large distances is tricky, as they simply look like points of light in even the best telescopes. Observations with spectroscopy (where light from an object is dispersed into its component colours) show that fast moving clouds of emitting material surround the disc but the true size of the disc and exact location of the clouds are very difficult to pin down.
Bruce will describe how astronomers can make use of cosmic coincidences, and benefit from a phenomenon described by Einstein’s general theory of relativity more than a century ago. In his seminal theory, Einstein described how light travels in curved paths under the influence of a gravitational field. So massive objects like black holes, but also planets and stars, can act to bend light from a more distant object, effectively becoming a lens.
A schematic diagram showing how microlensing affects our view of quasars (the most luminous AGNs). Credit: A. Bruce / Edinburgh. Click for a full size imageThis means that if a planet or star in an intervening galaxy passes directly between the Earth and a more distant AGN, over a few years or so they act as a lens, focusing and intensifying the signal coming from near the black hole. This type of lensing, due to a single star, is termed microlensing. As the lensing object travels across the AGN, emitting regions are amplified to an extent that depends on their size, providing astronomers with valuable clues.
Bruce and his team believe they have already seen evidence for two microlensing events associated with AGN. These are well described by a simple model, displaying a single peak and a tenfold increase in brightness over several years. MIcrolensing in AGNs has been seen before, but only where the presence of the galaxy was already known. Now Bruce and his team are seeing the extreme changes in brightness that signifies the discovery of both previously unknown microlenses and AGNs.
Bruce says: “Every so often, nature lends astronomers a helping hand and we see a very rare event. It’s remarkable that an unpredictable alignment of objects billions of light years away could help us probe the surroundings of black holes. In theory, microlensing could even let us see detail in accretion discs and the clouds in their vicinity. We really need to take advantage of these opportunities whenever they arise.”
There are expected to be fewer than 100 active AGN microlensing events on the sky at any one time, but only some will be at or near their peak brightness. The big hope for the future is the Large Synoptic Survey Telescope (LSST), a project the UK recently joined. From 2019 on, it will survey half the sky every few days, so has the potential to watch the characteristic changes in the appearance of the AGNs as the lensing events take place.
Media contacts
Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877 699
This email address is being protected from spambots. You need JavaScript enabled to view it.
Ms Anita Heward
Royal Astronomical Society
Mob: +44 (0)7756 034 243
This email address is being protected from spambots. You need JavaScript enabled to view it.
NAM 2016 press office (from Monday 27 June to Friday 1 July)
Tel: +44 (0)115 846 6993
An ISDN line and a Globelynx fixed camera are available for radio and TV interviews. To request these, please contact Robert or Anita.
Tracy Peet
University of Edinburgh
+44 (0)131 650 5362
This email address is being protected from spambots. You need JavaScript enabled to view it.
Science contact
Dr Alastair Bruce
University of Edinburgh
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Notes for editors
From Nobel laureates and Olympic champions to space explorers and prime ministers, the University of Edinburgh has been influencing history since it opened the gates to its first students in 1583.
The RAS National Astronomy Meeting 2016 (NAM 2016) takes place this year at the University of Nottingham from 27 June to 1 July. NAM 2016 brings together more than 550 space scientists and astronomers to discuss the latest research in their respective fields. The conference is principally sponsored by the Royal Astronomical Society and the Science and Technology Facilities Council. Follow the conference on Twitter
The University of Nottingham has 43,000 students and is ‘the nearest Britain has to a truly global university, with a “distinct” approach to internationalisation, which rests on those full-scale campuses in China and Malaysia, as well as a large presence in its home city.’ (Times Good University Guide 2016). It is also one of the most popular universities in the UK among graduate employers and the winner of ‘Outstanding Support for Early Career Researchers’ at the Times Higher Education Awards 2015. It is ranked in the world’s top 75 by the QS World University Rankings 2015/16, and 8th in the UK by research power according to the Research Excellence Framework 2014. It has been voted the world’s greenest campus for four years running, according to Greenmetrics Ranking of World Universities.
Impact: The Nottingham Campaign, its biggest-ever fundraising campaign, is delivering the University’s vision to change lives, tackle global issues and shape the future.
The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. STFC's Astronomy and Space Science programme provides support for a wide range of facilities, research groups and individuals in order to investigate some of the highest priority questions in astrophysics, cosmology and solar system science. STFC's astronomy and space science programme is delivered through grant funding for research activities, and also through support of technical activities at STFC's UK Astronomy Technology Centre and RAL Space at the Rutherford Appleton Laboratory. STFC also supports UK astronomy through the international European Southern Observatory. Follow STFC on Twitter
The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.
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AutoLens Analysis Steps Up for Euclid’s 100 000 Strong Gravitational Lens Challenge
Hubble Space Telescope imaging of the strong gravitational lens ER-0047-2808. Pictured in the centre of the image is the strong lens galaxy, whose mass is responsible for the deflection of the background source's light. The multiply-imaged source galaxy can be seen three times, as an extended arc to the south, a smaller arc to the north-east and two compact clumps of the light to the west. ESA/NASA/HST/STScI
The European Space Agency’s Euclid satellite, due for launch in 2020, will set astronomers a huge challenge: to analyse one hundred thousand strong gravitational lenses. The gravitational deflection of light from distant astronomical sources by massive galaxies (strong lenses) along the light path can create multiple images of the source that are not just visually stunning, but are also valuable tools for probing our Universe. Now, in preparation for Euclid’s challenge, researchers from the University of Nottingham have developed 'AutoLens', the first fully-automated analysis software for strong gravitational lenses. James Nightingale will present the first results from AutoLens at the National Astronomy Meeting 2016 in Nottingham on Friday, 1st July.
“AutoLens has demonstrated its capabilities with this stunning image of a strong gravitational lens system captured by the Hubble Space Telescope,” said Nightingale, who developed AutoLens together with his colleague, Dr Simon Dye. “The software's reconstruction of the lensed source reveals in detail a distant pair of star-forming galaxies that are possibly in the early stages of merging. Within the lensed image of the source are small-scale distortions, which encode an imprint of how the lens galaxy's mass is distributed. AutoLens has a novel new approach to exploit this imprinted information and can accurately measure the distribution of dark matter in the lensing galaxy.”
Historically, the analysis of strongly lensed images has been a very time consuming process, requiring a large amount of manual input to study just one system. To date, only around two hundred strong lens systems have been analysed. AutoLens can be run on ‘massively parallel’ computing architecture that uses multiple processors and requires no user input, so will be able to manage the huge amount of data delivered by the Euclid mission.
“Some of astronomy's most important results in the past five years have come from studying a handful of strong lenses. This small sample has allowed us to start to unravel the dark matter content of galaxies and the complex physics that drives their formation and evolution,” said Nightingale. “It will be breathtaking to embark on a study of up to one hundred thousand such systems. We can only speculate as to what it will reveal about the nature of dark matter and its role in galaxy evolution.”
Images
Hubble Space Telescope imaging of the strong gravitational lens ER-0047-2808. Pictured in the center of the image is the strong lens galaxy, whose mass is responsible for the deflection of the background source's light. The multiply-imaged source galaxy can be seen three times, as an extended arc to the south, a smaller arc to the north-east and two compact clumps of the light to the west.
Colour image: https://nam2016.org/images/nam2016/Media/Nightingale/ACS0047__Obs.png
Black and white image: https://nam2016.org/images/nam2016/Media/Nightingale/ACS0047__Obs2.png
AutoLens Source Reconstruction of the strong gravitational lens ER-0047-2808. The source is reconstructed using an adaptive pixel grid, which rebuilds the source's light using free-form pixels of any shape, size or tessellation. The reconstruction reveals two distinct galaxies under-going a major merger in the distant Universe.
Colour: https://nam2016.org/images/nam2016/Media/Nightingale/ACS0047__SrcRecon2.png
Black and white: https://nam2016.org/images/nam2016/Media/Nightingale/ACS0047__SrcRecon.png
Image credits: Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.
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Notes to editors
The RAS National Astronomy Meeting 2016 (NAM 2016, http://nam2016.org) takes place this year at the University of Nottingham from 27 June to 1 July. NAM 2016 brings together more than 550 space scientists and astronomers to discuss the latest research in their respective fields. The conference is principally sponsored by the Royal Astronomical Society and the Science and Technology Facilities Council. Follow the conference on Twitter via @rasnam2016
The University of Nottingham (http://nottingham.ac.uk/) has 43,000 students and is ‘the nearest Britain has to a truly global university, with a “distinct” approach to internationalisation, which rests on those full-scale campuses in China and Malaysia, as well as a large presence in its home city.’ (Times Good University Guide 2016). It is also one of the most popular universities in the UK among graduate employers and the winner of ‘Outstanding Support for Early Career Researchers’ at the Times Higher Education Awards 2015. It is ranked in the world’s top 75 by the QS World University Rankings 2015/16, and 8th in the UK by research power according to the Research Excellence Framework 2014. It has been voted the world’s greenest campus for four years running, according to Greenmetrics Ranking of World Universities.
Impact: The Nottingham Campaign, its biggest-ever fundraising campaign, is delivering the University’s vision to change lives, tackle global issues and shape the future.
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