Space Warps– II. New gravitational lens candidates from the CFHTLS discovered through citizen science
| Autor: | David Miller, Amit Kapadia, Rafael Küng, Christopher P. Davis, R. Gavazzi, Robert J. Simpson, Thomas E. Collett, Chris Lintott, Michael Parrish, Christine Macmillan, Surhud More, Arfon M. Smith, Claude Cornen, Edward Paget, Anupreeta More, Prasenjit Saha, Philip J. Marshall, Aprajita Verma, Elisabeth Baeten, Julianne K. Wilcox, Chris Snyder |
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| Přispěvatelé: | University of Zurich |
| Rok vydání: | 2015 |
| Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
530 Physics Calibration (statistics) astro-ph.GA Pipeline (computing) statistical [methods] ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION FOS: Physical sciences Sample (statistics) 10192 Physics Institute 01 natural sciences law.invention 1912 Space and Planetary Science law 0103 physical sciences Citizen science False positive paradox Computer vision 010303 astronomy & astrophysics Physics 010308 nuclear & particles physics business.industry Astronomy Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Galaxy Lens (optics) Gravitational lens Space and Planetary Science strong [gravitational lensing] Astrophysics of Galaxies (astro-ph.GA) astro-ph.CO 3103 Astronomy and Astrophysics Artificial intelligence business Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | More, A, Verma, A, Marshall, P J, More, S, Baeten, E, Wilcox, J, Macmillan, C, Cornen, C, Kapadia, A, Parrish, M, Snyder, C, Davis, C P, Gavazzi, R, Lintott, C J, Simpson, R J, Miller, D, Smith, A M, Paget, E, Saha, P, Küng, R & Collett, T E 2015, ' Space Warps II. New gravitational lens candidates from the CFHTLS discovered through citizen science ', Monthly Notices of the Royal Astronomical Society, vol. 455, no. 2, pp. 1191-1210 . https://doi.org/10.1093/mnras/stv1965 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stv1965 |
| Popis: | We report the discovery of 29 promising (and 59 total) new lens candidates from the CFHT Legacy Survey (CFHTLS) based on about 11 million classifications performed by citizen scientists as part of the first Space Warps lens search. The goal of the blind lens search was to identify lens candidates missed by robots (the RingFinder on galaxy scales and ArcFinder on group/cluster scales) which had been previously used to mine the CFHTLS for lenses. We compare some properties of the samples detected by these algorithms to the Space Warps sample and find them to be broadly similar. The image separation distribution calculated from the Space Warps sample shows that previous constraints on the average density profile of lens galaxies are robust. SpaceWarps recovers about 65% of known lenses, while the new candidates show a richer variety compared to those found by the two robots. This detection rate could be increased to 80% by only using classifications performed by expert volunteers (albeit at the cost of a lower purity), indicating that the training and performance calibration of the citizen scientists is very important for the success of Space Warps. In this work we present the SIMCT pipeline, used for generating in situ a sample of realistic simulated lensed images. This training sample, along with the false positives identified during the search, has a legacy value for testing future lens finding algorithms. We make the pipeline and the training set publicly available. Comment: 23 pages, 12 figures, MNRAS accepted, minor to moderate changes in this version |
| Databáze: | OpenAIRE |
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