Strong Lens Models for 37 Clusters of Galaxies from the SDSS Giant Arcs Survey*

Abstract

We present strong gravitational lensing models for 37 galaxy clusters from the SDSS Giant Arcs Survey. We combine data from multi-band Hubble Space Telescope WFC3 imaging, with ground-based imaging and spectroscopy from Magellan, Gemini, APO, and MMT, in order to detect and spectroscopically confirm new multiply-lensed background sources behind the clusters. We report spectroscopic or photometric redshifts of sources in these fields, including cluster galaxies and background sources. Based on all available lensing evidence, we construct and present strong lensing mass models for these galaxy clusters.

Efficient Mass Estimate at the Core of Strong Lensing Galaxy Clusters Using the Einstein Radius

“…The redshift range of the simulated SL sample,z L -0.16 0.67, is similar to that of the Sloan Giant Arc Survey (SGAS; M. Gladders et al 2020, in preparation;Bayliss et al 2011;Sharon et al 2020), which identified lensing clusters from giant arcs in shallow optical SDSS imaging. Future studies will extend to higher redshifts to complement surveys with samples of galaxy clusters out to z=1.75 such as the SPT-SZ 2500-square-degree survey (Bleem et al 2015).…”

“…The image plane of each cluster was generated multiple times, resulting in 5-24 ray-tracing realizations for each cluster halo. The background sources were randomly placed in areas of high magnification to produce highly magnified (total magnification >5) arcs easily detected from ground-based observations (e.g., Bayliss et al 2011;Sharon et al 2020).…”

“…The redshifts are a piece of information that ideally would be available to the lensing analysis, coming from spectroscopic follow-up (e.g., Sharon et al 2020) or using photometric redshifts (e.g., Molino et al 2017;Cerny et al 2018) from extensive multiband photometry. However, this may not always be the case, especially considering future large surveys where follow-up may be incomplete.…”

“…Studies of the mass profile of galaxy clusters can provide us with information related to evolution of structure, formation and feedback processes, and dark matter properties. The methods used to estimate the mass of galaxy clusters include X-ray (e.g., Vikhlinin et al 2009;Mantz et al 2018;Ettori et al 2019), the Sunyaev-Zel'dovich effect (SZ; Sunyaev & Zeldovich 1972, 1980e.g., Reichardt et al 2013;Sifón et al 2013;Planck Collaboration et al 2016), richness (e.g., Yee & Ellingson 2003;Koester et al 2007;Rykoff et al 2016), dynamics (e.g., Gifford & Miller 2013;Foëx et al 2017), and gravitational lensing (e.g., Kneib & Natarajan 2011;Hoekstra et al 2013;Sharon et al 2015Sharon et al , 2020. Gravitational lensing (weak and strong) is the best technique to probe the total projected (baryonic and dark matter) mass density, independent of assumptions on the dynamical state of the cluster or baryonic physics.…”

“…Advances in strong lens (SL) modeling, including a better understanding of SL systematics (Johnson & Sharon 2016), its effects on constraining cosmological parameters (Acebron et al 2017), magnification (Priewe et al 2017;Raney et al 2020), consequences due to the number of constraints (Mahler et al 2018), and the use of spectroscopic and photometric redshifts (Cerny et al 2018), make strong lens modeling a robust technique to study galaxy clusters and the background universe they magnify. A detailed lens model requires extensive followup: (1) imaging to identify multiple images and (2) spectroscopy of the lensed images to obtain spectroscopic redshifts of the sources (e.g., Johnson et al 2014;Zitrin et al 2014;Diego et al 2016;Kawamata et al 2016;Lotz et al 2017;Strait et al 2018;Lagattuta et al 2019;Sebesta et al 2019;Sharon et al 2020). The locations of the multiple images and the spectroscopic redshifts of the sources are used as constraints when computing the SL models.…”