Your work in print!: Space Warps CFHTLS papers accepted for publication

We’re really pleased to announce that our papers on the first Space Warps gravitational lens search on the Canada France Hawaii Telescope Legacy Survey (CFHTLS) have been accepted by the Monthly Notices of the Royal Astronomical Society, and will appear online and in print next month. In the meantime, you can find the accepted papers at Paper I & Paper II.

We’ve also resurrected the Space Warps site and are eagerly awaiting your classifications! You’ll be able to look at some CFHTLS images that have been seen before but we think are likely to contain interesting objects that didn’t quite make it into our final sample according to the analysis pipeline we ran while the project was live. Subsequently, Chris Davis, a research student who works with Phil at SLAC, put together an “offline” analysis that considers your classifications slightly differently. This threw up some new candidates that we would like your second opinion on. These may be false positives (i.e. objects that look like lenses but aren’t), difficult candidates (where you all didn’t agree), or genuinely missed candidates (not enough people viewed them). There’s an example of a missed simulated lens below. Check-out the Spotter’s Guide to refresh your memory on real lenses, false positives and artifacts. There are far fewer images this time round so you may find yourself out of subjects quickly.

We’ve also prepared a few articles from our home institutes that will come out today (Thursday 24th September) to mark the acceptance – a press release from Anu’s home institute in Tokyo, Kavli IPMU, a Symmetry article (online this afternoon) from SLAC, Phil’s home institute, and an Oxford Science Blog post from my home institute – so watch out for those!

We’re hoping that we may get to meet a few new lens spotters as a result of the articles, so please do help out any newbies you spot on Talk if you get the chance! Some of the images you see may already have been discussed on Talk as potential lenses as well, so please do add to those discussions too.

Happy classifying!


Example false negative

The image on the left shows a training image used in Space Warps. We inserted a simulated lens (top right) and this was presented as part of the classification stream. The right panel shows how it was classified by each viewer, the number of views increases from top to bottom. Each kink in the blue line indicates each new classification. Moves to the left indicate those who thought there was no lens here, and moves to the right show those who did. Overall the source stayed roughly 50:50, so the community classification for this object was undecided. A community classified lens candidate would lie to the right of this plot (trajectory crossing the blue dotted line on the right), and an image containing no lens candidate would cross the red dotted line on the left. Similarly, real (non-training/non-simulated) lenses may have been undecided in the CFHTLS search. We are now asking you to view some more images that could contain potential lens candidates that didn’t quite meet our detection threshold in the initial search.


2 responses to “Your work in print!: Space Warps CFHTLS papers accepted for publication”

  1. Pat says :

    Fermi Lab has posted an article about the paper in their on line magazine, Symmetry. Giving plenty of credit to Space Warps.

  2. Aprajita says :

    Hi Pat – thanks. Yes the Symmetry article is linked in the blog post, and thanks for emphasising it here.

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