A map of the distribution of supermassive black holes across the universe has helped astronomers prove that dark energy exists and that it causes space to expand faster and faster, according to an article published in the journal MNRAS.
“Now we understand how gravity works, but some issues of the structure of the Universe, such as the essence of dark energy, remain a mystery to us. We have long wanted to understand what it is, and projects like eBOSS are helping us to gradually add to our knowledge of the nature of the universe,”said William Percival of the University of Portsmouth, UK.
Dark skies
The BOSS project has been running as part of the "large" Sloan Digital Sky Survey (SDSS) since mid-2008. With its help, scientists are trying to find the so-called baryon acoustic oscillations (BAO) - "echoes" of the birth of the Universe in the form of acoustic waves, due to the movement of which irregularities arose in the distribution of matter that gave rise to modern galaxies and galaxy groups.
To do this, astronomers study the spectrum of quasars, the oldest, brightest and largest black holes in the centers of distant galaxies, observing how their light interacted with clouds of gas in the voids between the filaments of the "web of the universe" on the way to Earth. Comparing the differences in how light has changed during these travels from relatively distant and nearby galaxies, scientists track how fast the universe was expanding, and check whether this process occurred in the same way in different parts of it.
The first BOSS results were published four years ago. Tracking 60 thousand black holes, the most distant of which were at a distance of 11.5 billion light years from Earth, scientists have found no discrepancies between modern theoretical ideas about the properties of dark energy and what they observed in the spectra of these quasars.
On the other hand, similar discrepancies were recently found in the results of observations of relatively close to us supernovae and “pairs” of distant quasars. It turned out that today the Universe is expanding unexpectedly quickly - much faster than theory and calculations based on observations of the microwave "echo" of the Big Bang using the Planck telescope.
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Cosmic misreadings
This has led many physicists to question the existence of dark energy and the accelerating expansion of the universe. Recently, supporters and opponents of the "inflationary theory" entered into an open dispute on the pages of scientific journals and popular science publications.
For example, opponents of the expansion of the Universe called this idea anti-scientific, while its supporters accuse opponents of methodological errors. 33 leading cosmologists of the world, including Russian Andrei Linde, published a letter last week responding to criticism of skeptics.
Percival and his colleagues, including astrophysicists at the Institute for Nuclear Research of the Russian Academy of Sciences in Moscow, added fuel to the fire by publishing new data from the BOSS survey, which now includes over 176,000 galaxies and their black holes located 13 million light-years from Earth. In fact, they managed to build a three-dimensional map of galaxies and matter between them in a cube measuring 12 x 12 x 12 billion light years.
The new survey data, as astrophysicists say, generally correspond to the classical model of the structure of the Universe, which includes dark matter and dark energy. The expansion rate of the Universe in it, on the other hand, is closer to the "Planck" values than to the supernova data, which makes the discrepancies even more incomprehensible and interesting.
The further increase in the number of quasars and the discovery of more distant objects, as the participants hope, will help to check the results of "Planck" and understand which of the two expansion rates of the Universe is correct and how much dark energy is involved in this process.