Astrophysicists from the University of Hawaii in Manoa collected the largest collection of high-quality data on distances to galaxies, called Cosmicflows-4, using eight different methods, measured distances up to 56,000 galaxies.
There are several ways to measure distances to the galaxy. As a rule, individual researchers focus on one of them. In the new work, scientists aggregated individual observations from previous works and their own analysis, performed by two methods.
The galaxies are the building blocks of the universe, each of which is made up of several hundred billion stars. The galaxies, apart from the nearest gravitational forces associated with the Milky Way, are moving away the faster they are, as a result of the expansion of the universe that began at the time of the Big Bang. The measurements of the distances of the galaxy, together with information about their speeds far away, determine the magnitude of the universe and the time that has elapsed since its birth explain the authors of the work.
Since galaxies have been identified as separate from the Milky Way 100 years ago, astronomers have tried to measure distances to them all the time. Now, by combining our more precise and numerous tools, we can measure distances to the galaxies, as well as the corresponding rate of expansion of the universe and the time since the birth of the universe, to a few percent accuracy.
On the basis of measurements, researchers have estimated the value of the constant Hubble, which measures the rate of expansion of the universe. 56,000 galaxies indicate that the universe is expanding from 75 km/s to 1 Mpsk, with a measurement error of about 1.5 per cent.