RELICS: A Strong Lens Model for SPT-CLJ0615-5746, a z = 0.972 Cluster
Mahler, Guillaume; Frye, Brenda L.; Bradač, Maruša; Schrabback, Tim; Lovisari, Lorenzo; Stark, Daniel P.; Zitrin, Adi; Coe, Dan; Andrade-Santos, Felipe; Salmon, Brett; Sharon, Keren; Umetsu, Keiichi; Carrasco, Daniela; Cerny, Catherine; Czakon, Nicole G.; Dawson, William A.; Hoag, Austin T.; Huang, Kuang-Han; Johnson, Traci L.; Jones, Christine; Lam, Daniel; Mainali, Ramesh; Oesch, Pascal A.; Ogaz, Sara; Past, Matthew; Paterno-Mahler, Rachel; Peterson, Avery; Ryan, Russell E.; Sendra-Server, Irene; Vulcani, Benedetta; Bradley, Larry D.; Livermore, Rachael; Avila, Roberto J.
United States, Germany, Australia, Taiwan, Netherlands, Switzerland, Israel
Abstract
We present a lens model for the cluster SPT-CLJ0615-5746, which is the highest-redshift (z = 0.972) system in the Reionization of Lensing Clusters Survey, making it the highest-redshift cluster for which a full, strong lens model is published. We identify three systems of multiply imaged lensed galaxies, two of which we spectroscopically confirm at z = 1.358 and z = 4.013, which we use as constraints for the model. We find a foreground structure at z ∼ 0.4, which we include as a second cluster-sized halo in one of our models; however, two different statistical tests find the best-fit model consists of one cluster-sized halo combined with three individually optimized galaxy-sized halos, as well as contributions from the cluster galaxies themselves. We find the total projected mass density within r = 26.″7 (the region where the strong lensing constraints exist) to be M={2.51}-0.09+0.15× {10}14 M ⊙. If we extrapolate out to r 500, our projected mass density is consistent with the mass inferred from weak lensing and from the Sunyaev-Zel’dovich effect (M ∼ 1015 M ⊙). This cluster is lensing a previously reported z ∼ 10 galaxy, which, if spectroscopically confirmed, will be the highest-redshift strongly lensed galaxy known.