We have successfully acquired F110W (J-band) images of 68 massive elliptical galaxies in clusters and groups out to 80 Mpc by taking advantage of the efficient Hubble Space Telescope SNAP observing mode. We used the Surface Brightness Fluctuation (SBF) technique to measure distances to 44 of the galaxies so far with a typical uncertainty of ~5% in distance by implementing a new Python-based pipeline to simplify and automate the SBF analysis procedure. This new SNAP sample doubles the total number of IR SBF distances to galaxies beyond 50 Mpc. The new distances will allow for more accurate determination of the mass distribution in the local universe when combined with the Cosmicflows-4 database (Tully et al. 2022, arXiv:2209.11238). It will also provide a more precise comparison between early-type population distance indicators and distances derived from late-type galaxies via Cepheids well into the Hubble flow. These data will be combined with existing HST SBF distance measurements (Jensen et al. 2021, ApJS, 255, 21; Blakeslee et al. 2021, ApJ, 911, 65) to reduce the uncertainties in the local measurement of the Hubble Constant, which is currently at odds with the determination of the expansion rate at cosmological distances derived from cosmic microwave background fluctuations.
University / Institution: Utah Valley University
Format: In Person
SESSION D (3:30-5:00PM)
Area of Research: Science & Technology
Faculty Mentor: Joseph Jensen