TY - JOUR
T1 - Euclid Preparation XXXIII. Characterization of convolutional neural networks for the identification of galaxy-galaxy strong lensing events
AU - Euclid Collaboration
AU - Collaboration, Euclid
AU - Leuzzi, L.
AU - Meneghetti, M.
AU - Angora, G.
AU - Metcalf, R. B.
AU - Moscardini, L.
AU - Rosati, P.
AU - Bergamini, P.
AU - Calura, F.
AU - Clément, B.
AU - Gavazzi, R.
AU - Gentile, F.
AU - Lochner, M.
AU - Grillo, C.
AU - Vernardos, G.
AU - Aghanim, N.
AU - Amara, A.
AU - Amendola, L.
AU - Andreon, S.
AU - Auricchio, N.
AU - Bardelli, S.
AU - Bodendorf, C.
AU - Bonino, D.
AU - Branchini, E.
AU - Brescia, M.
AU - Brinchmann, J.
AU - Camera, S.
AU - Capobianco, V.
AU - Carbone, C.
AU - Carretero, J.
AU - Casas, S.
AU - Castellano, M.
AU - Cavuoti, S.
AU - Cimatti, A.
AU - Cledassou, R.
AU - Congedo, G.
AU - Conselice, C. J.
AU - Conversi, L.
AU - Copin, Y.
AU - Corcione, L.
AU - Courbin, F.
AU - Courtois, H. M.
AU - Cropper, M.
AU - Silva, A. Da
AU - Degaudenzi, H.
AU - Dinis, J.
AU - Dubath, F.
AU - Markovic, K.
AU - Gaztanaga, E.
AU - Nadathur, S.
PY - 2024/1/16
Y1 - 2024/1/16
N2 - Forthcoming imaging surveys will potentially increase the number of known galaxy-scale strong lenses by several orders of magnitude. For this to happen, images of tens of millions of galaxies will have to be inspected to identify potential candidates. In this context, deep learning techniques are particularly suitable for the finding patterns in large data sets, and convolutional neural networks (CNNs) in particular can efficiently process large volumes of images. We assess and compare the performance of three network architectures in the classification of strong lensing systems on the basis of their morphological characteristics. We train and test our models on different subsamples of a data set of forty thousand mock images, having characteristics similar to those expected in the wide survey planned with the ESA mission \Euclid, gradually including larger fractions of faint lenses. We also evaluate the importance of adding information about the colour difference between the lens and source galaxies by repeating the same training on single-band and multi-band images. Our models find samples of clear lenses with $\gtrsim 90\%$ precision and completeness, without significant differences in the performance of the three architectures. Nevertheless, when including lenses with fainter arcs in the training set, the three models' performance deteriorates with accuracy values of $\sim 0.87$ to $\sim 0.75$ depending on the model. Our analysis confirms the potential of the application of CNNs to the identification of galaxy-scale strong lenses. We suggest that specific training with separate classes of lenses might be needed for detecting the faint lenses since the addition of the colour information does not yield a significant improvement in the current analysis, with the accuracy ranging from $\sim 0.89$ to $\sim 0.78$ for the different models.
AB - Forthcoming imaging surveys will potentially increase the number of known galaxy-scale strong lenses by several orders of magnitude. For this to happen, images of tens of millions of galaxies will have to be inspected to identify potential candidates. In this context, deep learning techniques are particularly suitable for the finding patterns in large data sets, and convolutional neural networks (CNNs) in particular can efficiently process large volumes of images. We assess and compare the performance of three network architectures in the classification of strong lensing systems on the basis of their morphological characteristics. We train and test our models on different subsamples of a data set of forty thousand mock images, having characteristics similar to those expected in the wide survey planned with the ESA mission \Euclid, gradually including larger fractions of faint lenses. We also evaluate the importance of adding information about the colour difference between the lens and source galaxies by repeating the same training on single-band and multi-band images. Our models find samples of clear lenses with $\gtrsim 90\%$ precision and completeness, without significant differences in the performance of the three architectures. Nevertheless, when including lenses with fainter arcs in the training set, the three models' performance deteriorates with accuracy values of $\sim 0.87$ to $\sim 0.75$ depending on the model. Our analysis confirms the potential of the application of CNNs to the identification of galaxy-scale strong lenses. We suggest that specific training with separate classes of lenses might be needed for detecting the faint lenses since the addition of the colour information does not yield a significant improvement in the current analysis, with the accuracy ranging from $\sim 0.89$ to $\sim 0.78$ for the different models.
KW - astro-ph.GA
KW - Gravitational lensing: strong
KW - Methods: statistical
KW - Methods: data analysis
KW - Surveys
UR - https://doi.org/10.48550/arXiv.2307.08736
UR - https://www.aanda.org/for-authors/author-information/open-access
U2 - 10.1051/0004-6361/202347244
DO - 10.1051/0004-6361/202347244
M3 - Article
SN - 0004-6361
VL - 681
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A68
ER -