This paper presents the largest HST/WFC3 imaging survey to date, through which we measured the sizes of over 169 of the most massive galaxies in the CANDELS/3D-HST field. Because such massive galaxies are extremely rare, a large survey like this was essential to identify and study them in statistically meaningful numbers.

Although this was the most extensive high-resolution survey at the time, current observations with JWST—and future observations with the Roman Space Telescope—will allow us to extend this work to higher redshifts, larger galaxy samples, and a broader wavelength range. We have already begun this effort with the J-HIVE project, which will be a major focus of our future research.

The techniques used to measure galaxy sizes remain the same. Therefore, this paper is an important resource for learning and understanding the methodology of galaxy size measurements.