The phrase "same epoch" means that two or more things or people exist during the same period or timeframe. They share the same time in history. Full definition
In any case, the five poems represent the same epoch, the same experience, the same point of view. (religion-online.org)
The team sampled 151 luminous quasars at the same epoch as the HSC protoclusters and to their surprise found that most of those quasars are not close to the overdense regions of galaxies. (sciencedaily.com)
Stars indicate quasars and bright (faint) galaxies at the same epoch are shown as circles (dots). (sciencedaily.com)