Discovery “Ghost Galaxy” with 99.99% of dark matter – Observer

Two years ago, the teams of the WM Keck Observatory and the Gemini North Telescope (Hawaii) found a number of galaxies near the Milky Way that went unnoticed for decades in the eyes of astronomers. Now they have discovered why: one of these galaxies – Dragonfly 44 – has only 0.01% of stars. All remaining composition is dark matter, which makes it a real “ghost galaxy.”

Dragonfly 44 is 320 million light-years from the Milky Way, in a region called the set of Comma. On the global scale, this galaxy is practically our neighbor. At the time it was discovered, scientists explained that “while the Milky Way is a sea of ​​stars, these galaxies are like clouds tufts”.

Two years after these statements, the answers came. Dark matter is the glue that holds together the stellar matter of these galaxies. “They are trapped in their own shields that protect the fade,” can be read in the study published in the Astrophysical Journal Letters.

dark matter is a form of matter that does not interact with ordinary matter (that which consists of atomic particles) or herself. It has gravitational force but does not emit light or radiation. It is this that maintains the cohesion of the universe.

But what is the dark matter? Nobody knows for sure. It is known that it represents about 27% of all the mass and energy in the entire observable universe. It is also known that although its gravitational force is detectable by scientists, does not emit any form of light or radiation can be observed. While it remains a complete mystery to astronomers, it is clear that the dark matter is essential to universal stability. At breakneck speed with whom whirling galaxy, its gravitational forces are not enough to hold together: the dark matter that allows its cohesion. That is why, according to the cosmology model more accepted by the scientific community, for every gram of atoms that exists in the world, there are at least five times more dark matter.

The conclusions astronomers arrived on the Dragonfly 44 galaxy were obtained after measuring the velocities of the few stars that compose it. When registering these speeds over 33 hours and 30 minutes for six nights, scientists knew that they could discover the weight of the galaxy as a whole. This is possible because the higher the speed of a body, the greater its kinetic energy and its mass

In other words:. As these stars are faster, more massive galaxy is belonging. Now, the Dragonfly 44 stars move at 47 kilometers per second, so it is a billion times more massive than the sun. All normal? Not really. When they arrived at these figures, scientists turned up their noses:. This galaxy was too heavy for the gravitational force of the stars was enough to hold together

kinetic energy is that which a body is on the move. The higher the speed of a body, the greater its kinetic energy. When the body is resting, the kinetic energy is zero

It was so concluded last:. A galaxy with these characteristics has to be made 99.99% of dark matter. It is not an isolated phenomenon: there is a similar galaxy in the Virgo Cluster but, according to calculations published earlier this year, has only 99.96% of dark matter. Now, these galaxies will be laboratories of astronomers who want to discover what is truly dark matter.