Hundreds of thousands of filaments dangling through the Milky Way present a strange mystery.
These long, magnetized filaments, glistening in radio waves, are observed for the first time from other galaxies. They’re not exclusive to the Milky Way, thus the diversity of environments whereby they can be found is helping scientists to identify the mechanisms that can cause them.
Astrophysicist Farhad Yusuf Zadeh of Northwestern University in the US initially found the Milky Way’s filaments in the 1980s, and is puzzling over them since then.
There’re two plausible explanations for this, according to Yusuf Zadeh. The first is an interaction between large clouds and galaxies. The second is turbulence inside weak magnetic fields brought on by the motion of galaxies.
“We know a lot about filaments within our very own Galactic Center, and now filaments are starting showing up as a new population of extragalactic filaments,” Yusuf Zadeh said.
The underlying physical systems for both filament populations are identical, despite the vastly different locations, “he said. Items are part of the very same family, but the filaments outside the Milky Way are more mature, distant cousins, and I mean really distant (time as well as space) cousins.
More or less 1,000 of these filaments have been found to date in the Milky Way, measuring up to 150 light years in length and hanging in strangely neat and orderly arrangements like harp strings, most recently thanks to the MeerKAT radio telescope in South Africa.
The telescope is sensitive observations of the galactic center – penetrating through the heavy dust and gas that obscures much of what’s inside – expanded the number of filaments known previously by a factor of 10. These radio observations also demonstrated that the filaments have cosmic ray electrons spinning in magnetic fields close to the speed of light and that magnetic fields are amplified around the entire length of all the filaments.
It would be difficult without more info, to find out the reason they are there, hanging quietly in the galactic center. The discovery of more filaments, in four diverse galaxy clusters ranging between 163 million as well as 652 million light-years away, is an enormous breakthrough.
“After examining filaments for all these years in our very own Galactic Center, I was very excited to see these tremendously beautiful structures,” Yusuf Zadeh said. “we found these filaments someplace in the Universe, it indicates that something common is happening,” he said.
The newly discovered filaments away from the Milky Way are in a number of essential ways different from the thread-like structures in our world. They are associated with jets and lobes of radio galaxies – large structures, which erupt from the galactic center, spanning vast distances on both sides of the galactic plane. The filaments extending from these lobes and jets are additionally much bigger compared to structures observed in the Milky Way center, between 100 and 1,000 times bigger.
A few of them possess incredible length – around 200 kiloparsecs, “Yusuf-Zadeh explained.
“That is more or less four or five times bigger than the size of the entire Milky Way,” she said. It’s astonishing how long their electrons remain together. If an electron travelled over the filament length at the speed of light, it would take it 700,000 years. Plus they don’t travel at the speed of light.
Additionally they are older and more fragile in magnetic fields. Additionally they extend into intergalactic space, usually at right angles to the planes. The Milky Way’s filaments seem to be focused on the galaxies disk.
But on the flip side, there’re substantial parallels. Extragalactic and galactic filaments possess identical length-to-width ratio, and the cosmic ray transport mechanism will be the exact same. In case the same mechanism creates all of the filaments, then it has to be something which works at different scales.
One of those mechanisms could be the wind. Lively supermassive black holes as well as unrestrained star formation can produce galactic winds which extend into intergalactic space. These gusts might drive into the tenuous clouds of gas and dust drifting through intergalactic and interstellar space, pressing the material to produce filamentary structures.
Yet another prospect was discussed by simulations: Turbulence produced in the environment by gravitational events. This particular turbulence may result in eddies in the intergalactic medium around which weak magnetic fields get snagged, folded and ultimately stretched into filaments with powerful magnetic fields.
It is not yet a clear answer. We still do not know if exactly the same mechanism is responsible for both filaments, or if totally different phenomena produce components which look extremely similar.
“All these filaments happen to be very old outside our universe,’ Yusuf-Zadeh said.
They’re nearly from a different time of our Universe, but they’re indicating to the inhabitants of the Milky Way that the same origin is present because of the creation of filaments. ” I believe this’s remarkable.”
The research has been published in The Astrophysical Journal Letters.
