A measurement of the Hubble constant from angular diameter distances to two gravitational lenses

The local expansion rate of the Universe is parametrized by the Hubble constant, , the ratio between recession velocity and distance. Different techniques lead to inconsistent estimates of . Observations of Type Ia supernovae (SNe) can be used to measure , but this requires an external calibrator to convert relative distances to absolute ones. We use the angular diameter distance to strong gravitational lenses as a suitable calibrator, which is only weakly sensitive to cosmological assumptions. We determine the angular diameter distances to two gravitational lenses, and megaparsec, at redshifts and . Using these absolute distances to calibrate 740 previously measured relative distances to SNe, we measure the Hubble constant to be kilometers per second per megaparsec.

Source: ScienceNOW - September 11, 2019 Category: Science Authors: Jee, I., Suyu, S. H., Komatsu, E., Fassnacht, C. D., Hilbert, S., Koopmans, L. V. E. Tags: Astronomy, Physics r-articles Source Type: news