Jensen, Joseph B.Joseph B.JensenBlakeslee, John P.John P.BlakesleeMa, Chung-PeiChung-PeiMaMilne, Peter A.Peter A.MilneBrown, Peter J.Peter J.BrownCANTIELLO, MicheleMicheleCANTIELLOGarnavich, Peter M.Peter M.GarnavichGreene, Jenny E.Jenny E.GreeneLucey, John R.John R.LuceyPhan, AnhAnhPhanTully, R. BrentR. BrentTullyWood, Charlotte M.Charlotte M.Wood2025-04-032025-04-0320210067-0049http://hdl.handle.net/20.500.12386/37029We measured high-quality surface brightness fluctuation (SBF) distances for a sample of 63 massive early-type galaxies using the WFC3/IR camera on the Hubble Space Telescope. The median uncertainty on the SBF distance measurements is 0.085 mag, or 3.9% in distance. Achieving this precision at distances of 50-100 Mpc required significant improvements to the SBF calibration and data analysis procedures for WFC3/IR data. Forty-two of the galaxies are from the MASSIVE Galaxy Survey, a complete sample of massive galaxies within ~100 Mpc; the SBF distances for these will be used to improve the estimates of the stellar and central supermassive black hole masses in these galaxies. Twenty-four of the galaxies are Type Ia supernova hosts, useful for calibrating SN Ia distances for early-type galaxies and exploring possible systematic trends in the peak luminosities. Our results demonstrate that the SBF method is a powerful and versatile technique for measuring distances to galaxies with evolved stellar populations out to 100 Mpc and constraining the local value of the Hubble constant. * Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. These observations are associated with GO Programs #11711, #11712, #12450, #14219, #14654, #14771, #14804, #15265, and #15329.STAMPAen10.3847/1538-4365/ac01e7https://iopscience.iop.org/article/10.3847/1538-4365/ac01e72021ApJS..255...21JFIS/05 - ASTRONOMIA E ASTROFISICA