Dark matter has been around for a long time, and even the galaxies that existed 10 billion years ago had almost as much dark matter as the galaxies that exist today. This theory contradicts earlier studies that suggest the early universe had less dark matter around galaxies.
According to Alfred Tiley, the lead author of the study who is also an astronomer at Durham University in England:
“Dark matter was similarly abundant in star-forming galaxies in the distant past as it is in the present day. It wasn’t a complete surprise, but in reality, we didn’t know whether the observational reality would align with expectations from theory.”
His research was recently sent to the journal Monthly Notices of the Royal Astronomical Society.
Almost 85% of the total mass of the known universe is made up from dark matter, but this substance doesn’t interact with light, which baffles scientists because they cannot view it. However, they can spot its gravitational pull on the normal matter – the one that makes up stars, nebulas, planets, and everything from trees, people and rocks on Earth.
Usually, dark matter clumps in halos around a galaxy, according to the rotation of the galaxies.
The study recently published used information from two surveys of 1,500 star-forming galaxies and calculated the rotation of galaxies back in time – 10 billion years ago.
Dark Matter Amounts May Vary Within Individual Galaxies
In an interview with Live Science, Alfred Tiley stated the following:
“Our estimate of the amount of dark matter in galaxies is an average for the whole population at each epoch. The amount of dark matter within individual galaxies might vary significantly.”
He and his team found that the dark matter around the galaxies was equal as the one in the galaxies in our present universe. However, the study contradicts previous studies where they found that galaxies had less dark matter than the younger galaxies. The lead author of one of the previous studies, Reinhard Genzel, who is an astronomer at the Max Planck Institute for Extraterrestrial Physics in Garching, explained that the recent research “uses only one of the four independent approaches we had used to come to our conclusion.”
Tiley explained that computer simulations studied by Genzel showed very high-mass galaxies, which are rare in the distant universe:
“It appears [their] results apply to very massive galaxies at this distant epoch but may not be representative of galaxies with comparatively lower stellar masses, like those that we studied in our work.”
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.