An artist’s impression of a vast disc of water orbiting a supermassive black hole in a remote galaxy. By measuring maser emissions from such discs, astronomers can pin down the distance to the host galaxy. That data, in turn, can be used to calculate the Hubble constant. Image: Sophia Dagnello, NRAO/AUI/NSF
A new set of precision distance measurements made with an international collection of radio telescopes have greatly increased the likelihood that theorists need to revise 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 expansion rate of the Universe, a value important for testing the theoretical model describing the composition and evolution of the Universe. The problem is that the new measurements exacerbate a discrepancy between previously measured values of the Hubble Constant and the value predicted by the model when applied to measurements of the cosmic microwave background made by the Planck satellite.
“We find that galaxies are nearer than predicted by the standard model of cosmology, corroborating a problem identified in other types of distance measurements,” said James Braatz, of the National Radio Astronomy Observatory (NRAO). “There has been debate ...