Program: GS-2021A-C-3

Title:Rosetta Stones: assembling the red sequence at z=1.
PI:Sarah Sweet
Co-I(s): Karl Glazebrook, Tucker Jones, Keerthi Chandrasekaran, Nicha Leethochawalit, Trevor Mendel, Thomas Collett, Colin Jacobs, Dorota Bayer, Jean Brodie, Evan Kirby, Zhuyun Zhuang

Abstract

The red sequence of galaxies represents the bulk of stellar mass in the local Universe. Galaxy assembly onto the red sequence takes a variety of paths. While most elliptical galaxies were quenched after z=1, a new survey for lensed galaxies has uncovered some rare exceptions. The Rosetta Stones are lensed images of a quiescent galaxy at z=1.01596 with a stellar mass of just 10^10.5 Msun. The 7x magnification combined with the fortitous AO star yield a truly rare opportunity for accurately measuring the size and morphology of this pioneering arrival to the red sequence.