Space mystery: Darkest galaxies provide startling clues on dark matter

A previous study report had suggested that 95 percent of the universe is comprised of a dark fluid with negative mass

dark matter
Composite image of the Perseus galaxy cluster using data from NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton and Hitomi, a Japanese-led X-ray telescope. X-ray: NASA/CXO/Fabian

Dark matter is one of the most mysterious entities in the universe, and until now, scientists have not succeeded in decoding the internal mechanisms of this form of matter. But now, a new study conducted on low-surface brightness (LSB) galaxies is apparently shedding light on dark matter.

Dark matter's interaction with bright matter

During the study, researchers analyzed the speed at which stars and gases that compose the galaxies rotate, and scientists noted that low-surface brightness galaxies have a very homogenous behavior. This result obtained by scientists provides clues and the presence of dark matter, and its interaction with the bright matter.

"We have found that disc galaxies can be represented by a universal relationship. In particular, in this study we analyzed the so-called Low-Surface-Brightness (LSB) galaxies, a particular type of galaxy with a rotating disc called this way because they have a low-density brightness," said Chiara di Paolo, an astrophysicist at Sissa (International School for Advanced Studies) (SISSA Scuola Internazionale Superiore di Studi Avanzati), Italy, in a recent statement.

Can we see dark matter?

Scientists believe that dark matter comprises 90 percent of the universe. Even though it cannot be observed directly because it does not emit light, dark matter's effects can be detected on other objects in the cosmos. Until now, scientists believe that a gravitational interaction used to happen between dark matter and objects in space, but this new research suggests that another type of direct interaction may happen involving dark matter.

"We have discovered relationships of scale between the properties of the stellar disc and those of the dark matter halo, for example, a relationship between the dimensions of the stellar discs and the dimensions of the internal region with a constant density of the dark matter halo. Furthermore, by comparing the relationships found in the LSB with those obtained in different types of galaxies, we have found that they are all almost coincidental. And it has been a great surprise to verify that galaxies with very different morphology and history show the same relationships between the properties of dark matter and those of luminous matter," added Di Paolo.

Is there dark fluid in the universe?

As debates surrounding dark matter go on in full swing, another study report which was published a few months back had suggested that the universe is made up of a dark fluid with negative mass. This study conducted by a team of experts at the University of Oxford led by Jamie Farnes suggested that this unified dark fluid of negative masses is a hypothetical form of matter with negative gravity that repels all other materials around them.

After put forwarding this new hypothesis, researchers added that it will answer two baffling space mysteries; why galaxies hold together, and why the universe expands at an accelerating pace every time.