English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Aims: In this work, we aim to provide a reliable list of gravitational lens(GL) candidates based on a search performed over the entire Gaia Data Release 2(Gaia DR2). We also show that the sole astrometric and photometric informationscoming from the Gaia satellite yield sufficient insights for supervisedlearning methods to automatically identify GL candidates with an efficiencythat is comparable to methods based on image processing. Methods: We simulated106,623,188 lens systems composed of more than two images, based on a regulargrid of parameters characterizing a non-singular isothermal ellipsoid lensmodel in the presence of an external shear. These simulations are used as aninput for training and testing our supervised learning models consisting ofExtremely Randomized Trees. The latter are finally used to assign to each ofthe 2,129,659 clusters of celestial objects a discriminant value that reflectsthe ability of our simulations to match the observed relative positions andfluxes from each cluster. Once complemented with additional constraints, thesediscriminant values allowed us to identify GL candidates out of the list ofclusters. Results: We report the discovery of 15 new quadruply-imaged lenscandidates with angular separations less than 6" and assess the performance ofour approach by recovering 12 out of the 13 known quadruply-imaged systems withall their components detected in Gaia DR2 with a misclassification rate offortuitous clusters of stars as lens systems that is below one percent.Similarly, the identification capability of our method regardingquadruply-imaged systems where three images are detected in Gaia DR2 isassessed by recovering 10 out of the 13 known quadruply-imaged systems havingone of their constituting images discarded. The associated misclassificationrate varying then between 5.8% and 20%, depending on the image we decided toremove.

Gaia GraL: Gaia DR2 Gravitational Lens Systems. III. A systematic blind search for new lensed systems