It turns out that the universe is expanding faster than expected, thanks to the results of this measurement. Scientists describe the expansion of the universe as a process of dark energy. And the latter is often defined by a cosmological constant, first described by Albert Einstein. Now the result of a new study shows that the cosmological constant may not be as constant as it is.
It may increase.
The speed of space expansion is called the Hubble constant. Determining its exact size is very difficult. Almost every research leads to different results. Recently, according to Planck Satellite Surveillance Microwave Surveillance, this constant is megaparsec 67.4 kilometers per second, with a maximum error of 1 percent.
Other methods of measurement are often based on "standard candles" or objects of known brightness (stars with cephalides or type Ia supernovae) whose distance can be determined by absolute light.
Last year's calculation based on cefeids was 73.5 (km / s) / Mpc. So, after assessing such a huge difference in the results, one can understand why astronomers are worried about measuring after measurements.
But a few years ago, astronomers realized that it was possible to determine the distance and another type of object – quasars and black holes.
Quasars are one of the most significant objects in the universe. These are the core galaxies – September, because the central supermassive black hole in the galaxy actively brings the surrounding material. Visual and Radio Spectrum Emissions are caused by the rotating material of the control disk – this material, as if water flowing into the drain hole, rotated to produce huge friction and heat,
Quasars also emit X-rays and ultraviolet rays. Guido Risaliti, a scientist from the University of Florence (Italy) and Elisabeth Lusso, a scientist at Darhem University (UK), found that the ratio of these two wavelengths differs with absolute ultraviolet light.
When this light is known (can be counted in proportion), quasar can be used as any other "standard candle".
This means that measurements can be made for the future of the universe.
"The use of quasars as standard candles has great potential because we see them far behind the supernova type Ia, so we see a much earlier epoch in space history," Lucas said.
Scientists calculated 1,598 quasars, glowing from 1.1 to 2.3 billion. Since the beginning of the universe, the data of ultraviolet light and the distance of these celestial bodies has calculated the speed of expansion of the early Universe.
They also compared the results of the expansion velocity of the universe calculated on the basis of the type Ia supernova with the last result in a somewhat later period of about 9 billion dollars. years after the beginning of the Universe, and the results are very similar. However, the rate of expansion of the first universe does not correspond to the predicted growing rate of expansion of the universe of the standard cosmological model.
"We have observed quasars just billions of years after the Great Blast, and we have found that the rate of expansion of the universe has so far been greater than it was supposed to be, which means that the dark energy is strengthening with the aging of the universe," Risaliti said.
In fact, we do not know what dark energy is – we can not even measure it. It's just the name we gave an unknown push force that seems to increase the expansion of the universe over time.
According to the rate of space expansion, astrophysicists estimate dark energy should be about 70 percent. all universes, so adjusting the expansion rate allows us to calculate more accurately the amount of dark energy.
If the density of dark energy increases over time, then, according to scientists, it should mean that Einstein's cosmological constant is not constant. However, this would explain the strange number of measurements and perhaps the differences between previously measured Hubble constants.
But to say something with certainty requires independent verification of these measurement results.
"This model is quite interesting because it can help solve two tasks at the same time, but there is no ultimate solution to the problem, and before we say that this cosmic puzzle is solved, we will have to look much more closely into more models. resolution of these inconsistencies may require new physics, including the possibility of increasing dark energy, and our new results support such considerations, "says Risaliti.
The results of the study were published by Nature Astronomy and the article is read in full by ArXiv.