Magellan LDSS3 Survey

The Magellan/LDSS3 survey (PIs Sharon, Stark) targets 21 RELICS clusters visible from the southern hemisphere (see table). The survey is designed to make redshift confirmation via detection of [OII] emission line at z~ 0.5-1.7 and Lyman-alpha emission at z > 2.5. With the broad wavelength coverage (4250-10000 Angstrom) of LDSS3, we could also observe any strong UV metal lines at z>1. In total, we had 10 LDSS3 nights for this program. Ramesh analyzed all reduced spectra of ~200 objects to estimate redshifts. The final catalog includes redshift confirmation from 58 lensed galaxies in 18 (out of 21 observed) RELICS clusters. This also includes a new sample of 13 Lyman-alpha emitting galaxies at z~3-5. These redshift measurements have provided better constraints on strong lensing analysis. Some of these results have already appeared in recent RELICS papers (Cerny et al. 2018, Paterno-Mahler et al. 2018, Acebron et al. 2018b, Mahler et al. 2018).