8 may 2013

Join the search for 'space warps'

Science

Space warps closeup
Spotting a space warp (centre) in an image of thousands of other galaxies is tricky [Image: Space Warps Collaboration/CFHT/Terapix]

Online volunteers are being asked to search for 'space warps', very rare massive galaxies that bend light around them so that they act rather like giant lenses in space. By looking through data that has never been seen by human eyes, citizen scientists can help astronomers discover some of the rarest objects in the Universe.

Visitors to www.spacewarps.org,  which launches today (8 May 2013), are being asked to spot these important astronomical objects, more commonly called 'gravitational lenses', in hundreds of thousands of deep sky images.  Armchair astronomers could be the first humans to see these galaxies, each one of which is several billion light years away. By spotting space warps, they will help uncover the role dark matter plays in how galaxies form.

'Not only do space warps act like lenses, magnifying the distant galaxies behind them, but we can also use the light they distort to weigh them, helping us to figure out how much dark matter they contain and how it’s distributed,' said Dr Phil Marshall of Oxford University's Department of Physics, who is one of the leaders of the research team. 'Gravitational lenses help us to answer all kinds of questions about galaxies, including how many very low mass stars such as brown dwarfs – which aren't bright enough to detect directly in many observations – are lurking in distant galaxies.'

'The Zooniverse has always been about connecting people with the biggest questions and now, with Space Warps, we're taking our first trip to the early Universe. We're excited to let participants and planetarium visitors be the first to see some of the rarest astronomical objects of all,' said Dr Arfon Smith, Director of Citizen Science at the Adler Planetarium in Chicago home to the team who built the Space Warps site.

The Space Warps project is a lens discovery engine. Joining the search is easy: visitors to the website are given examples of what space warps look like and are shown how to mark potential candidates on each image. The first set of sky images to be inspected in this project is from the CFHT (Canada-France-Hawaii Telescope) legacy survey.

'Computer algorithms have already scanned the images from the CFHT survey, but there are likely to be many more space warps that the algorithms have missed. Realistic simulated space warps are dropped into some images to train the volunteers how to spot them, and reassure people that they are on the right track,' said Dr Anupreeta More, project co-lead from Kavli IPMU, Tokyo.

Previous studies have shown that the human brain is better at identifying complex lenses than computers are, and that members of the public can be at least as good at spotting astronomical objects as experts. The team describe the project as a collaboration between humans and computers, as data from the human volunteers will help to train computers to become better space warp spotters.

'Even if individual visitors only spend a few minutes glancing over 40 or so images each that's really helpful to our research – we only need a handful of people to spot something in an image for us to say that it’s worth investigating,' said Dr Aprajita Verma of Oxford University, space warps' third principal investigator.

After identifying possible space warp candidates in images, people will be able to discuss them on an online forum with other volunteers and experts, and even create computer models of their discoveries. The final sample of space warp candidates will be published for both amateur and professional astronomers to investigate further.

space warps search