Huge patch of universe is strangely opaque despite its lack of galaxies



Just the fact that we live in a universe is sometimes a mystery. But fortunately our cosmic house is a place that follows rules; the laws of physics seem to be agreed everywhere, and galaxies are uniformly distributed throughout. Except in this 300 million year old region, which seems to be missing something.

Scientists observed an opaque space area for a quasar, an extra bright light source, in the distance. They realized that this light-blocking area had confusingly fewer galaxies than they had expected.

The region lies in front of a quasar called ULAS J0148 + 0600, whose light has been left on its journey to us when the universe was less than a billion years old. This area seems to absorb light over a period of more than 300 million light years.

The team of scientists used the Subaru telescope in Hawaii to search for distant galaxies around the opaque region and found it much less than average, according to the article published in The Astrophysical Journal . This is the opposite of what you would expect – should an opaque area have no matter?

This apparent inconsistency could help scientists better understand the nature of the early cosmos.

"It gives us a chance to study a place in the universe that lags behind the rest of the universe," George Becker, a scholar of the University of California, Riverside, studied. Gizmodo .

Astronomers view distant objects through their "Lyman alpha" emissions, light emitted by hydrogen atoms with a characteristic wavelength. The light traverses the expanding universe, through which the wavelength extends along the road.

But stuff in the intervening space, especially neutral atoms, can absorb the light and cause certain wavelengths to disappear from the signal that is received on earth. By mapping the wavelengths of the light of a distant quasar, you can make a map and a timeline of the intervening things.

Becker and his team explained that electrically neutral gas absorbs the Lyman alpha light, but does not use ionised gas, atoms that lack electrons. The area of ​​the universe closest to us is relatively uniform and there is a lot of ultraviolet light to keep the gas ionized and prevent absorption.

But things might not be that uniform in the early universe. Perhaps places with more galaxies had more ultraviolet radiation, which meant more ionization, and those areas were therefore more transparent. But regions such as those for this quasar had fewer galaxies, which means less ionisation, and were therefore opaque.

It is an interesting observation that is counter-intuitive in different ways. "The exciting part is that this is a very large structure about which something else is," said Martin Haehnelt, an astronomer at the University of Cambridge in the United Kingdom who was not involved in the study, Gizmodo . "There should be the same number of galaxies in one region as in another," but in this case they are not.

Becker told Gizmodo that this region might tell a story about the era of re-ionization – the period early in the history of the universe after the first stars were formed and exploded in supernovae, ionizing neutral gas molecules. . Perhaps certain regions of heaven have entered this period later than others.

There is more work to do to explain the mystery, and this region is only a skewer of the enormous sky. If this idea is correct, then zones of the air with more galaxies at this distance should have less Lyman-alpha light absorption.

But although the laws of physics remain constant, there seem to be parts of the universe that are different from the rest.

[ApJ]


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