2026-04-13T07:56:11Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/2211242025-05-23T20:30:58Zcom_2072_1057col_2072_478904col_2072_478917

2025-05-23T20:30:57Z urn:hdl:2445/221124 Nine lensed quasars and quasar pairs discovered through spatially extended variability in Pan-STARRS Dux, F. Lemon, C. Courbin, Frédéric Neira, Favio Anguita, Timo Galan, A. Kim, Sam Hempel, Maren Hempel, Angela Lachaume, Régis Gravitació Quàsars Gravitation Quasars We present the proof of concept of a method for finding strongly lensed quasars using their spatially extended photometric variability through difference imaging in cadenced imaging survey data. We applied the method to Pan-STARRS, starting with an initial selection of 14 107 Gaia multiplets with quasar-like infrared colours from WISE. We identified 229 candidates showing notable spatially extended variability during the Pan-STARRS survey period. These include 20 known lenses and an additional 12 promising candidates for which we obtained long-slit spectroscopy follow-up. This process resulted in the confirmation of four doubly lensed quasars, four unclassified quasar pairs, and one projected quasar pair. Only three are pairs of stars or quasar+star projections. The false-positive rate accordingly is 25%. The lens separations are between 0.8100 and 1.2400, and the source redshifts lie between z = 1.47 and z = 2.46. Three of the unclassified quasar pairs are promising dual-quasar candidates with separations ranging from 6.6 to 9.3 kpc. We expect that this technique is a particularly efficient way to select lensed variables in the upcoming Rubin-LSST, which will be crucial given the expected limitations for spectroscopic follow-up. 2025-05-23T20:30:57Z 2025-05-23T20:30:57Z 2025-05-20T06:43:12Z 2025-05-20T06:43:12Z 2024-01-31 2025-05-20T06:43:13Z info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/2445/221124 Reproducció del document publicat a: https://doi.org/10.1051/0004-6361/202347598 Astronomy & Astrophysics, 2024, vol. 682 https://doi.org/10.1051/0004-6361/202347598 cc-by (c) Dux, F. et al., 2024 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess EDP Sciences