Space Warps: I. Crowd-sourcing the discovery of gravitational lenses

We describe SpaceWarps, a novel gravitational lens discovery service that yields samples of high purity and completeness through crowd-sourced visual inspection. Carefully produced colour composite images are displayed to volunteers via a webbased classification interface, which records their estima...

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Hauptverfasser: Marshall, P, Verma, A, More, A, Davis, C, More, S, Kapadia, A, Parrish, M, Snyder, C, Wilcox, J, Baeten, E, Macmillan, C, Cornen, C, Baumer, M, Simpson, E, Lintott, C, Miller, D, Paget, E, Simpson, R, Smith, A, Küng, R, Saha, P, Collett, T
Format: Journal article
Veröffentlicht: Oxford University Press 2015
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author Marshall, P
Verma, A
More, A
Davis, C
More, S
Kapadia, A
Parrish, M
Snyder, C
Wilcox, J
Baeten, E
Macmillan, C
Cornen, C
Baumer, M
Simpson, E
Lintott, C
Miller, D
Paget, E
Simpson, R
Smith, A
Küng, R
Saha, P
Collett, T
author_facet Marshall, P
Verma, A
More, A
Davis, C
More, S
Kapadia, A
Parrish, M
Snyder, C
Wilcox, J
Baeten, E
Macmillan, C
Cornen, C
Baumer, M
Simpson, E
Lintott, C
Miller, D
Paget, E
Simpson, R
Smith, A
Küng, R
Saha, P
Collett, T
author_sort Marshall, P
collection OXFORD
description We describe SpaceWarps, a novel gravitational lens discovery service that yields samples of high purity and completeness through crowd-sourced visual inspection. Carefully produced colour composite images are displayed to volunteers via a webbased classification interface, which records their estimates of the positions of candidate lensed features. Images of simulated lenses, as well as real images which lack lenses, are inserted into the image stream at random intervals; this training set is used to give the volunteers instantaneous feedback on their performance, as well as to calibrate a model of the system that provides dynamical updates to the probability that a classified image contains a lens. Low probability systems are retired from the site periodically, concentrating the sample towards a set of lens candidates. Having divided 160 square degrees of Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) imaging into some 430,000 overlapping 82 by 82 arcsecond tiles and displaying them on the site, we were joined by around 37,000 volunteers who contributed 11 million image classifications over the course of 8 months. This Stage 1 search reduced the sample to 3381 images containing candidates; these were then refined in Stage 2 to yield a sample that we expect to be over 90% complete and 30% pure, based on our analysis of the volunteers performance on training images. We comment on the scalability of the SpaceWarps system to the wide field survey era, based on our projection that searches of 105 images could be performed by a crowd of 105 volunteers in 6 days.
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spelling oxford-uuid:cbcd307f-70db-4af4-b4b6-e4ca752bea972022-03-27T07:17:33ZSpace Warps: I. Crowd-sourcing the discovery of gravitational lensesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:cbcd307f-70db-4af4-b4b6-e4ca752bea97Symplectic Elements at OxfordOxford University Press2015Marshall, PVerma, AMore, ADavis, CMore, SKapadia, AParrish, MSnyder, CWilcox, JBaeten, EMacmillan, CCornen, CBaumer, MSimpson, ELintott, CMiller, DPaget, ESimpson, RSmith, AKüng, RSaha, PCollett, TWe describe SpaceWarps, a novel gravitational lens discovery service that yields samples of high purity and completeness through crowd-sourced visual inspection. Carefully produced colour composite images are displayed to volunteers via a webbased classification interface, which records their estimates of the positions of candidate lensed features. Images of simulated lenses, as well as real images which lack lenses, are inserted into the image stream at random intervals; this training set is used to give the volunteers instantaneous feedback on their performance, as well as to calibrate a model of the system that provides dynamical updates to the probability that a classified image contains a lens. Low probability systems are retired from the site periodically, concentrating the sample towards a set of lens candidates. Having divided 160 square degrees of Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) imaging into some 430,000 overlapping 82 by 82 arcsecond tiles and displaying them on the site, we were joined by around 37,000 volunteers who contributed 11 million image classifications over the course of 8 months. This Stage 1 search reduced the sample to 3381 images containing candidates; these were then refined in Stage 2 to yield a sample that we expect to be over 90% complete and 30% pure, based on our analysis of the volunteers performance on training images. We comment on the scalability of the SpaceWarps system to the wide field survey era, based on our projection that searches of 105 images could be performed by a crowd of 105 volunteers in 6 days.
spellingShingle Marshall, P
Verma, A
More, A
Davis, C
More, S
Kapadia, A
Parrish, M
Snyder, C
Wilcox, J
Baeten, E
Macmillan, C
Cornen, C
Baumer, M
Simpson, E
Lintott, C
Miller, D
Paget, E
Simpson, R
Smith, A
Küng, R
Saha, P
Collett, T
Space Warps: I. Crowd-sourcing the discovery of gravitational lenses
title Space Warps: I. Crowd-sourcing the discovery of gravitational lenses
title_full Space Warps: I. Crowd-sourcing the discovery of gravitational lenses
title_fullStr Space Warps: I. Crowd-sourcing the discovery of gravitational lenses
title_full_unstemmed Space Warps: I. Crowd-sourcing the discovery of gravitational lenses
title_short Space Warps: I. Crowd-sourcing the discovery of gravitational lenses
title_sort space warps i crowd sourcing the discovery of gravitational lenses
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