{"paper":{"title":"Gaia GraL: Gaia DR2 Gravitational Lens Systems. IV. Keck/LRIS spectroscopic confirmation of GRAL113100-441959 and model prediction of time-delays","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Alberto Krone-Martins, C\\'eline Boehm, Christine Ducourant, Daniel Stern, Eric Slezak, Fran\\c{c}ois Mignard, George Djorgovski, Jean-Fran\\c{c}ois LeCampion, Jean Surdej, Joachim Wambsganss, Jonas Kl\\\"uter, Laurent Galluccio, Ludovic Delchambre, Matthew J. Graham, Olivier Wertz, Ramachrisna Teixeira, Ulrich Bastian","submitted_at":"2018-10-05T11:41:28Z","abstract_excerpt":"We report the spectroscopic confirmation and modeling of the quadruply imaged quasar GRAL113100-441959, the first gravitational lens (GL) to be discovered mainly from astrometric considerations. Follow-up spectra obtained with Keck/LRIS reveal the lensing nature of this quadruply-imaged quasar with redshift $z_s = 1.090 \\pm 0.002$, but show no evidence of the central lens galaxy. Using the image positions and $G$-band flux ratios provided by Gaia Data Release 2 as constraints, we model the system with a singular power-law elliptical mass distribution (SPEMD) plus external shear, to different l"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.02624","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/1810.02624/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}