J/MNRAS/522/1091ivo://CDS.VizieR/J/MNRAS/522/1091CDSLagattuta D.J.Richard J.Ebeling H.Basto Q.Cerny C.Edge A.,Jauzac M.Mahler G.Massey R.2026-07-27T12:56:42Z2026-07-27T13:55:48ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxy-clustersgalaxiesgravitational-lensingphotometryspectroscopyvisible-astronomyinfrared-astronomyWe present the first strong-gravitational-lensing analysis of the galaxy cluster RX J0437.1+0043 (RXJ0437; z = 0.285). Newly obtained, deep MUSE observations, Keck/MOSFIRE near-infrared spectroscopy, and Hubble Space Telescope SNAPshot imaging reveal 13 multiply imaged background galaxies, three of them (at z = 1.98, 2.97, and 6.02, respectively) in hyperbolic umbilic (H-U) lensing configurations. The H-U images are located only 20-50 kpc from the cluster centre, i.e. at distances well inside the Einstein radius where images from other lens configurations are demagnified and often unobservable. Extremely rare (only one H-U lens was known previously) these systems are able to constrain the inner slope of the mass distribution - and unlike radial arcs, the presence of H-U configurations is not biased towards shallow cores. The galaxies lensed by RXJ0437 are magnified by factors ranging from 30 to 300 and (in the case of H-U systems) stretched nearly isotropically. Taking advantage of this extreme magnification, we demonstrate how the source galaxies in H-U systems can be used to probe for small-scale (10^9^M_{sun}_) substructures, providing additional insight into the nature of dark matter.2023MNRAS.522.1091Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/522/1091CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/514/497 : HST/MUSE study of galaxies in Abell 370 (Lagattuta+, 2022)J/MNRAS/485/3738 : 3D structure in the A370 MUSE Mosaic (Lagattuta+, 2019)J/MNRAS/473/663 : MUSE and HFFs Photometry of A2744 (Mahler+, 2018)J/MNRAS/469/3946 : Abell 370 MUSE redshifts (Lagattuta+, 2017)J/MNRAS/318/333 : Extended ROSAT Bright Cluster Sample (Ebeling+ 2000)J/A+A/646/A83 : 12 massive lensing clusters MUSE observationsJ/A+A/628/A3 : LAE z~3-7 luminosity functions (de La Vieuville+, 2019)J/ApJ/668/643 : Multiply imaged gravitational lens systems (Limousin+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/522/1091https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/522/1091http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/522/1091https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/522/1091https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/522/1091http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/522/1091GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/522/1091/tablea1 (Final redshift catalogue of detected lensed sources in galaxy cluster RX J0437.1+0043)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/522/1091/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/522/1091/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/522/1091/tablea1?GETtext/xml+votable180.050000true69.30019933587310.72488489118690.0055555555555555566/22955https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/522/1091?format=asciiOpticalInfrareddefaultJ/MNRAS/522/1091/tablea1Final redshift catalogue of detected lensed sources in galaxy cluster RX J0437.1+0043recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDA numerical identifier for each object, typically matched to a sextractor detection run (ID)meta.id;meta.mainintSourceAn indication of how the object was detected (Source) (1)meta.codecharRAJ2000The 2D spatial right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000The 2D spatial declination (J2000) (Dec)degpos.eq.dec;meta.mainzThe measured redshift of each object (z)src.redshiftfloatq_zThe redshift measurement reliability quality flag from low as 1 to high as 3 (zconf) (2)meta.code.qual;src.redshiftintMultIDThe unique image number as seen in section 2.2 Keck observations data (Mult_ID) (3)meta.codechar