Astronomers think they may have found giant invisible structures lurking in the Milky way. These things seem to be pretty big approximately the size of Earths orbit around the Sun and they could help to explain where a bunch of missing matter in the universe is, known as the missing baryon problem.
The detection of these structures was make use of astronomers working at the CSIROs Compact Array telescope in eastern Australia. Although previous research had hinted at their presence before, this new paper published in the publication Science helps to hold different sizes and shape a bit better.
Dont think these are big, solid objectsthough. Basically, the structures appear to be big clumps of some sort of material, maybe clouds of cool gas, in the existing thin gas that lies between stars. And they appear to be in odd shapes. The astronomers described them as looking like hollow noodles or hazelnuts with material on the outside and a hollow centre. Some may even be sheet-like, and we could be looking at them edge-on.
Where they came from, how old they are, or how many there could be in our galaxy remains a mystery, though. Its all guesswork at this stage, lead writer Keith Bannister of CSIRO told IFLScience. There could be many thousands of these in the galaxy.
The CSIRO’s Compact Array in Australia, demonstrated, was used to stimulate the discovery.Alex Cherney
The structures were found by observing the lensing impact they produced on remote galaxies. In this case, one in particular was find refracting, or bending, the lighting from a remote bright object called a quasar inside a galaxy, named PKS 1939315, in June 2014. As the light passes through the structures on its way to us, it gets distorted, specifically in the radio wavelength band.
Its not quite the same effect as gravitational lensing, where a massive objectbends the lighting of a more remote one, rendering impacts like an Einstein Ring. But the interesting thing is that the structures dont have an effect on the optical brightness, indicating they are devoid of dust or other more solid material.
The lensing here is plasma lensing, and its exactly the same as refraction, such as how eye glasses run, told Bannister. He also likened it to light passing through a wine glass.
We also know their velocity. They are moving at about 50 kilometers( 30 miles) per second through the interstellar medium, and the ones that have been detected so far reside about 3,000 light-years away. But the really interesting part of all this is that these previously unseen structures could be accounting for a large fraction of hidden mass in the Milky Way.
Bannister was quick to point out that they have nothing to do with dark matter. The existence of dark matter is often inferred from how galaxies are able to hold themselves together, despite their rotation. These structures are not thought to play a part in that.
Instead, they may play a part in the lesser-known missingbaryon problem. That arises from the very successful hypothesi of the Big Bang, explains Bannister. The quirky bit is that it tells us that approximately 4 percent of the universe should be made of atoms, baryons, things that make up you and me.
The problem is, counting up all the matter we can see doesnt account for 4 percent of the universe. So to resolve the problem, something else must be out there and perhaps these invisible structures, at the least in optical wavelengths, hold the answer.
Were hoping that with our run, it could spur a bit of theoretical postulation as to how these things might have formed, told Bannister.