Astronomers found it difficult to explain the transparency of the Universe

Астрономы затруднились объяснить прозрачность Вселенной

The mechanism of the “enlightenment” of the Universe remain the subject of debate among cosmologists.

Scientists deepened the mystery of the “enlightenment” of the Universe in the first era of her life after the Big Bang, accurately measuring the power of gamma-ray flares in nearby galaxies. It is clearly not enough to make intergalactic space is transparent to light, the scientists write in the journal MNRAS.

“We didn’t know what role was played by the stars in the ionization of the intergalactic medium for one simple reason – we do not understand which part of the produced light escapes beyond their galaxies. Our measurements indicate very small role stars in this process, which is very problematic from the point of view of current theories,” write Neil Tanvir (Nial Tanvir) from the University of Leicester (UK) and his colleagues.

After the Big Bang and the initial expansion of the Universe when it was dominated by high energy and light, its substance is quickly cooled, and it was complete darkness. When lit the first stars, the darkness dissipated not immediately.

Scientists call these the “dark ages” era of reionizatsii for the reason that at this time, the universe gradually became transparent and visible as a result of the ionization of clouds of hydrogen in the first galaxies and voids between them.

The monitoring of space telescope, “plank”, and WMAP confirms the existence of this period, however its duration and the mechanism of “enlightenment” of the Universe remain the subject of debate among cosmologists.

For example, some scientists believed that the main engine of this process could be the first supermassive black holes producing huge amounts of ultraviolet radiation and x-rays. Other experts disagree with them, and credited the role of the first stars, which had an unusual composition, size, and unusually short time of life.

Tanvir and dozens of astrophysicists from Europe, China and the United States clarified the role of the first luminaries in reionizatsii of the universe, traced for nearly a hundred of the most powerful explosions in the Universe – the most powerful gamma-ray flares.

Many astronomers assume that they occur during explosions, especially big stars, and on the first phases of their transformation into black holes. When such a star dies, the force of attraction resulting black hole or neutron star is so high that emitted clouds of matter former luminaries are combined into a “donut” which revolves around a Central object.

A portion of this disk is absorbed by a black hole, and the remainder accelerates to near-light speeds and are emitted to the outer space in the form of jets, narrow beams of matter. During this “promotion” of the matter of the dying star generates so much energy and light, how much the star class of the Sun produces in its entire life. How exactly is this process, scientists still do not know and arguing about it fact over the past 50 years.

The first galaxies of the Universe, as cosmologists now believe, was almost entirely populated by stars that can give rise to such outbreaks. Given the extremely high rate of star formation in those times, like gamma-ray bursts and ultraviolet glow of their progenitors, according to supporters of this theory, was to play a significant role in the “enlightenment” of the universe.

Tanvir and his colleagues found that it most likely wasn’t. Observations and relatively close, and distant gamma-ray bursts show that only 0.5% of their light fails to “punch” the gas and dust cocoons surrounding the galaxy, and out into the space between them.

This value is approximately an order of magnitude less that predicted theory.

Such findings indicate that current cosmological calculations, involving a leading role of stars and supernovae in “prosvetlenie” of the Universe, should be radically revised.

As suggested by the authors, the main driving factor in this process was the supermassive black holes with relatively modest mass, which we can’t see because of the low sensitivity of the telescopes. On the other hand, they do not exclude more exotic scenarios such as the decay of dark matter particles.


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