In a video from the European Southern Observatory (ESO), astronomers may have discovered that dark matter may have been less influential in the creations of new galaxies than previously thought. The minute video, briefly explained that dark matter, around 10 billion years ago, was not as concentrated and had little influence on galaxies’ rotations. The dark matter, according to the ESO, took longer to shrink than ordinary matter.
Dark matter is a type of matter that remains unidentified and is different from dark energy, normal matter, and neutrinos. Dark matter does not emit or interact with light and remains virtually invisible to the electromagnetic spectrum, in other words, dark matter observes light making it difficult to see. While it has not been seen, astronomers have found evidence of its influence on galaxies. Scientists are currently experimenting with ways to observe dark matter, but none has been seen or identified.
Reinhard Genzel led a group of astronomers at the Max Planck Institute for Extraterrestrial Physics in Germany used instruments in Chile at ESO’s Very Large Telescope to observe peak galaxy formation around 10 billion years ago. According to the press release from the ESO, the lack of dark matter during formation is in “stark contrast” to the influence of dark matter in galaxies today.
The ESO’s Very Large Telescope measured the “rotation of six massive, star-forming galaxies” and found that the outer regions rotated slower than places closer to the center. What this means, according to the press release, is that the core had less dark matter to influence the rotation. This finding surprised astronomers. Genzel, the lead author of the study published in Nature, said that the early galaxies were “dominated” by ordinary matter than dark matter. He went on to say that the first galaxies were more turbulent than spiral galaxies that are seen in the Earth’s cosmic neighborhood.
The further in time, the astronomers looked, the less dark matter seemed to be present in the creation of galaxies. This says that three or four billion years following the Big Bang, the gas in galaxies condensed into rotating discs that appeared flat, with dark matter that surrounded the galaxies were less concentrated, according to EurekAlert!. Black matter, it is speculated, took more time than regular matter to condense into the force that influences galaxies today. This theory seems to fall in line with observations of early galaxies that were compact and had more gas.
Besides the six galaxies, the researchers examined, they also peered at about another 100 fainter galaxies, according to Space.com. On average, the team’s findings were consistent. Further research will be conducted on smaller galaxies to “get a better picture of the broader population of galaxies and their evolution,” Genzel said.
By Cheryl Werber
Photo Courtesy ESO/L. Calçada