Archive | December 2013

Seasons Greetings from Space Warps: Some Refined Lenses, and a Big Thank You!

Well, Space Warps Refine has been running for just over a week, and it’s had a fantastic response from you all. THANK YOU! With over 140,000 classifications of the 3679  images, we have very good data on almost all of them – and some exciting new lens candidates are popping out of the pipeline!

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Here’s one: a nice example of a small lensing cluster, with a longish gravitational arc. We think this probably wasn’t picked up by the robotic ArcFinder because it has such low surface brightness, and the field is so crowded. 

Here’s another good one: a binary lens?  The blue arc looks like its composed of three merging images of a small blue background galaxy, strongly lensed by the lower red galaxy. But what’s that yellow object? It’s a little bigger than a star would be, so it’s probably another massive galaxy – and its colour suggests that it’s at a lower redshift than the lens galaxy. If it is in the foreground, then it is lensing both the blue arc, and the red lens! So-called “compound lenses” like these are very interesting: we might be able to learn about the mass of the yellow galaxy as well as the red one. With enough examples of systems like this we might even be able to say something about how fast the Universe is expanding… Tom’s written a paper on this that you might find interesting.

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New lenses are not the only things turning up from the Refinement analysis: there are a very small number of false positives sneaking through, but as you might expect, they are pretty convincing imposters! Follow the links in the images’ comments feeds to see the problems with this apparent Einstein Ring, and this nice looking bright arc!

We’ll leave the images on Space Warps Refine up over the holiday period to give you the chance to classify as many of them as you want, and in the New Year we’ll do the final analysis of their probabilities taking all your votes into account. Just as we had hoped for, it looks very much like the outcome will be a short list of very good lens candidates, ranked by probability. An excellent publishable result! When we have the final list, we’ll be taking it to Talk, and starting the process of capturing, with your help, all your investigations of them, including the zoomed in views that show the lens configurations best, and the models that you have been making.

So, it’s been a wonderful first year for Space Warps: a more or less completed first project, and some exciting new lens candidates. Next year, we’ll be back with some new survey data – a new challenge for you.

Thanks very much for all your contributions – we hope you all have a very good holiday season!

Phil, Aprajita and Anupreeta

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