Automatic detection of gravitational arcs in wide-area survey data, comparison of the observed and the theoretically expected arc abundance
Final Report Abstract
Within the one funded year of this project, we could address two of the originally planned goals: Our arcfinder software, developed for the automatic and blind detection of gravitationally-lensed arcs near the detection limit in noisy images, could be applied to survey data, and progress was made on the calibration of the arcfinder with realistically simulated images. Moreover, the arcfinder was supplemented by post-processing filters suppressing spurious detections. Contrary to the original plans, we used the data from the COSMOS survey to apply the arcfinde to. The two main reasons were that the COSMOS data had previously been inspected for strong gravitational lensing events by eye, suggesting a comparison between the arcfinder results and the human classification on a moderately large data set. For the arcfinder calibration off simulated images, dedicated software for realistic image simulation developed jointly with collaboration partners in Bologna was used to create arcs near the detection threshold in noisy data. With those, the arcfinder detections were tested for completeness as a function of limiting arc magnitude under varying simulated observing conditions. Finally, the arcfinder was applied to a sample of well-defined galaxy clusters to quantify their strong-lensing properties.
Publications
- (2008). Gravitational lenses and lens candidates identified from the COSMOS field. Monthly Notices of the Royal Astronomical Society, 389(3), 1311-1318
Jackson, N.
(See online at https://doi.org/10.1111/j.1365-2966.2008.13629.x) - (2008): First Catalog of Strong Lens Candidates in the COSMOS Field. In: ApJS 176 (1), S. 19–38
Faure, C., Kneib, J.-P., Covone, G., Tasca, L., Leauthaud, A. et al.
(See online at https://doi.org/10.1086/526426) - (2010). The lensing efficiencies of MACS X-ray-selected versus RCS optically selected galaxy clusters. Monthly Notices of the Royal Astronomical Society, 406(2), 1318-1336
Horesh, A., Maoz, D., Ebeling, H., Seidel, G. & Bartelmann, M.
(See online at https://doi.org/10.1111/j.1365-2966.2010.16763.x)
