The best and brightest high redshift candidates
magnified by gravitational lensing

Building on the successes of CLASH and the Frontier Fields, and optimizing our survey for high-redshift discovery, RELICS has delivered candidates for the brightest galaxies known in the first billion years at z ~ 6 (Salmon et al. 2017) and the most distant galaxy lensed to form an arc at z ~ 10, observed 500 million years after the Big Bang (Salmon et al. 2018). These will be prime targets for follow-up study with current and future facilities including ALMA and JWST.


RELICS science topics include:
• high-redshift galaxies
• cluster mass scaling relations
• supernovae to empirically test lensing models
• dark matter particle constraints

Left: SPT0615-JD at z ~ 10, the most distant lensed arc known (Salmon et al. 2018). See our NASA/STScI press release.


RELICS is obtaining the first HST infrared imaging of some of the most massive clusters according to Planck. Our less massive clusters are generally known to be exceptional lenses with existing ACS imaging.


Press release, Scientific American article, and color images of RELICS clusters.

Left: RXC0232-44, courtesy ESA Picture of the Week


We obtained 188 HST orbits (PI Coe) and 946 Spitzer hours (PI Bradač) to observe 46 fields strongly lensed by 41 massive galaxy clusters plus 19 blank fields in parallel (6' away).

Other pages

  • Data

    No proprietary period. Reduced HST images and catalogs delivered within 2-3 months of final epochs.

  • Publications

    Papers, posters, and presentations based on RELICS data.

  • Team

    Our international collaboration of experts.

  • Internal

    Team-only access.

Support for program GO-14096 is provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555