New precision distance measurements with a set of radio telescopes has increased the probability of revision of the “standard model” that describes the fundamental nature of the Universe. The new distance measurements allowed astronomers to refine their calculation of the Hubble constant, the rate of expansion of the universe, an important value to test the theoretical model that describes the composition and evolution of the universe. The problem is that the new measurements exacerbate a discrepancy between the previously measured values of the Hubble constant and the value predicted by the model when applied to measurements of the cosmic microwave background by the Planck satellite.
“We found that galaxies are closer than predicted by the standard cosmology model, corroborating a problem identified in other types of distance measurements. It has been debated whether this problem lies in the model itself or in the measurements used to test it. Our work uses a distance measurement technique completely independent of all the others, and we reinforce the disparity between the measured and predicted values. The problem is likely to be the basic cosmological model involved in predictions, “James Braatz said in a statement. , from the National Radio Astronomy Observatory (NRAO).
Braatz leads the Megamaser Cosmology Project, an international effort to measure the Hubble constant by finding galaxies with specific properties that lend themselves to producing precise geometric distances. The project has used the Very Long Baseline Array (VLBA) of the National Science Foundation, the Very Large Array (VLA) of Karl G. Jansky and the Robert C. Byrd Green Bank (GBT) Telescope, together with the Effelsberg telescope in Germany . The team reported their latest results in Astrophysical Journal Letters.