It appears that dark matter has been sticking to galaxies for an extended period, so those early galaxies that emerged about 10 billion years ago possessed as much dark matter as the galaxies of today do. That is the result of a new study that identified that the dark matter from the early Universe was as prevalent as it is nowadays, contradicting previous studies that indicated otherwise.
“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,” said Alfred Tiley, an astronomer at Durham University in England and lead author on the new study.
Dark matter totals for up to 85% of the known Universe, but the scientists do not know much about this mysterious substance and its origins. Also, astronomers cannot see dark matter in the Universe, so they can only spot it thanks to its gravitational pull on the ordinary matter, the so-called baryonic matter.
Dark Matter From The Early Universe Spotted By Scientists
In a new study, astronomers gathered and analyzed data from two surveys of 1,500 star-forming galaxies to estimate rotation rates for galaxies going back 10 billion years, as Live Science reported. By calculating the galactic rotation in the early Universe, scientists measured the average by grouping the galaxies by distance and then cataloging them by their light.
“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,” explained Tiley for Live Science.
“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,” said Alfred Tiley, referring to the previous studies on dark matter in the early Universe.
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