It is the first time that part of this structure has been observed, a vast network of filaments of matter that extends throughout the Universe
S. Cantalupo, UC Santa Cruz A distant quasar, more than ten billion light years, has served to illuminate the telara ac smica A distant quasar, more than ten billion light years from us, recently discovered by astronomers at the University of California, has served to illuminate, as if from a large space lantern It will be a fragment of the vast network of filaments of matter that connect the galaxies to each other as a great tensor smica It is the first time that a part of this structure has been visualized, predicted by the current cosmolytic theories but never observed until now. The finding is published today in Nature.
Using the ten meter telescope Keck I, in Hawaii, the researchers managed to detect a huge, long and bright gas nebula extending over two million light years into the intergalactic space.
It is an exceptional object - says Sebastiano Cantalupo, an astronomer at the University of Santa Cruz and the main author of the article. It is large, at least twice as much as any nebula detected so far, and extends far beyond the galactic environment in which the quasar is located.
The standard cosmolytic model, which describes the structure and formation of the Universe, predicts that galaxies are `` embedded '' in a kind of `` conservative '' earthquake. Matter, most of which (84%), in addition, is impossible to see because it is made of dark matter.
This web appears in the computer simulations of the evolution and structure of the Universe, which show the distribution of matter (ordinary and dark) at very large scales, and that include both the halos of dark matter inside whose galaxies themselves form as the filamentous web of filaments that connects them to each other. The force of gravity forces ordinary matter, which we can see, to follow the distribution of dark matter, so that scientists have long been trying to locate a distribution pattern that looks like the one seen in simulations With dark matter.
Until now, however, no one had managed to visualize one of these filaments. It is true that intergalactic gas clouds had previously been detected, but the way in which they are distributed in space had never been seen. In this study, however, scientists have had an exceptional ally: A quasar, a very active core of some galaxies, whose intense radiation causes the hydrogen in the gas cloud to fluoresce and shine.
“This quasar - explains J. Xavier Prochaska, co-author of the study - is illuminating the gas at scales that go far beyond anything else we have seen so far, giving us the first portrait of the filaments of matter that extend between galaxies. Which has given us an excellent view of the overall structure of our Universe. ”
The hydrogen illuminated by the quasar emits a type of ultraviolet light known as “Lyman alpha radiation”. But the distance at which the quasar is located is so large (ten billion light years) that the emitted light has “stretched” due to the expansion of the Universe, moving from an invisible wavelength to a visible violet shadow and, therefore, capable of being detected by the Keck. Knowing the distance at which the quasar is, the astronomers calculated the wavelength of the detected Lyman alpha radiation and built a special filter so that the telescope's spectrometer could obtain images at that wavelength.
"We have studied other quasars in this way without detecting any filament of gas, " Cantalupo explains. The light of the quasar is like the beam of a flashlight, and this time we were lucky that the flashlight was pointing right towards the nebula and making its gas glow. We believe that it is a part of a filament that can be much longer, but from which we can only see the part that is illuminated by the quasar beam of light. ”
Dark galaxies
A quasar is a class of active galactic nucleus that emits intense radiation fed by the supermassive black hole in the center of the galaxy. In previous attempts to search for extragalactic gas filaments illuminated by quasars, Cantaloupe and other astronomers managed to discover the first "dark galaxies", the dense gas "knots" of the cosmic web, where the filaments meet. These dark galaxies are called that because they have no stars. They are believed to be too small, or too young, to form them.
“The dark galaxies - Cantalupo affirms - are clouds of gas much denser and smaller than other parts of the cosmic web. In the image we have obtained, dark galaxies can also be seen, in addition to the filament, much more diffuse and extensive ”.
Researchers believe that the amount of gas in the nebula is at least ten times greater than what the simulations predict. "We think there may be more gas inside the cosmic web than the simulations predict, " Cantalupo says. Our observations are challenging what we knew about intergalactic gas and providing us with a new laboratory in which to test and refine our models. ”
Abjini Arráizwww.portalterraluz.com
Blog: www.portalterraluz.wordpress.com
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