Gravitationally Lensed High-Redshift Galaxy Candidates

This is a color composite image of the Hubble Ultra Deep Field. Green circles mark the locations of candidate galaxies at a redshift of z~8, while higher-redshift candidates are circled in red. The estimated distances to these candidates have not been confirmed spectroscopically. About 20 to 30 percent of these high-z galaxy candidates are very close to foreground galaxies, which is consistent with the prediction that a significant fraction of galaxies at very high redshifts are gravitationally lensed by individual foreground galaxies. This will help as a guide for future observations planned for the James Webb Space Telescope when it is launched.