Detailed observations of star forming galaxies at high redshift are critical to understand the formation and evolution of the earliest galaxies. Gravitational lensing provides an important boost, allowing observations at physical scales unreachable in unlensed galaxies. We present three lensed galaxies from the RELICS survey at zphot=6−10, including the most highly magnified galaxy at zphot∼6 (WHL0137-zD1, dubbed the Sunrise Arc), the brightest known lensed galaxy at zphot∼6 (MACS0308-zD1), and the only spatially resolved galaxy currently known at zphot∼10 (SPT0615-JD). The Sunrise Arc contains seven star-forming clumps with delensed radii as small as 3 pc, the smallest spatial scales yet observed in a z>6 galaxy, while SPT0615-JD contains features measuring a few tens of parsecs. MACS0308-zD1 contains a r∼30 pc clump with a star formation rate (SFR) of ∼3M⊙ yr−1, giving it a SFR surface density of ΣSFR∼103M⊙ yr−1 kpc−2. These galaxies provide a unique window into small scale star formation during the Epoch of Reionization. They will be excellent targets for future observations with JWST, including one approved program targeting the Sunrise Arc.
@article{arxiv.2207.03532,
title = {RELICS: Small-scale Star Formation in Lensed Galaxies at $z = 6-10$},
author = {Brian Welch and Dan Coe and Adi Zitrin and Jose M. Diego and Rogier Windhorst and Nir Mandelker and Eros Vanzella and Swara Ravindranath and Erik Zackrisson and Michael Florian and Larry Bradley and Keren Sharon and Maruša Bradač and Jane Rigby and Brenda Frye and Seiji Fujimoto},
journal= {arXiv preprint arXiv:2207.03532},
year = {2023}
}