VizieR Online Data Catalog: Strong lens models for 37 clusters from SGAS (Sharon+, 2020)

The SDSS Giant Arcs Survey (SGAS)-HST program (GO-13003, PI: Gladders) consists of 107 orbits of HST imaging during Cycle 20 (spanning 2012 Nov to 2013 Oct). Each cluster was imaged with four WFC3 filters over three orbits. The GO-13003 observations were obtained with both the near-infrared (IR) and ultraviolet-visible (UVIS) channels of the WFC3 instrument.

We supplement our observations with archival optical WFPC2 data from programs GO-11974 (PI: Allam) and GO-11100 (PI: Bradac), which were available for five fields. Subsequent HST programs of some of these targets acquired grism spectroscopy or additional bands, including GO-14622 (PI: Whitaker), GO-14230 (PI: Rigby), and GO-14896 (PI: Bayliss).

Several different programs conducted spectroscopy of SGAS fields, using multiple observatories (see Section 3.2). In this paper, we present new spectroscopic redshifts from Gemini and Magellan multi-slit spectroscopic programs. Table 2 lists for each cluster the best available spectroscopic redshift, from the new observations described here, supplemented with information from previous programs including Bayliss+ (2011, J/ApJS/193/8 and 2014ApJ...783...41B), public databases (e.g., SDSS), and the literature.

Spectroscopic observations of SGAS clusters were obtained using the Gemini North telescope as part of programs GN-2015A-Q-38 (PI: Sharon; 2015 Apr 18,19) and GN-2015B-Q-26 (PI: Sharon; 2015 Oct-2016 Feb) using the Gemini Multi-Object Spectrograph (GMOS). We also report redshifts from program GN-2011A-Q-11 (PI: Gladders; 2011 May-2012 Apr) of primary arcs and cluster members that were not published elsewhere.

We followed up clusters that are observable from the south, with DEC<20°, with the Magellan 6.5m telescopes at Las Campanas Observatory, Chile. We observed eight cluster fields with the Inamori-Magellan Areal Camera & Spectrograph (IMACS) on the Baade telescope, using multi-slit spectroscopy. We report redshifts in two cluster fields that we observed with the Low Dispersion Survey Spectrograph 3 (LDSS3) camera on the Clay telescope. We report new redshift measurements in three fields: SDSSJ0333-0651, SDSS J0928+2031, and SDSS J1439+1208, using the Folded-port InfraRed Echellette (FIRE) on the Baade telescope. The observations took place on 2013 March 1. Observations with the Dual Imaging Spectrograph (DIS) on the 3.5m telescope at Apache Point Observatory (APO) on 2012 January 20 were used to measure the redshifts of two arcs in this paper. Observations with the 6.5m Multiple Mirror Telescope (MMT) using the Blue Channel spectrograph were obtained on 2014 May 4 (PI: Bayliss) for one of the targets in this paper, the giant arc in SDSSJ1456+5702.

(5 data files).