Astronomers have discovered the largest rotating structures in the Universe by&nbsp;mapping the motion of galaxies in huge filaments that connect the cosmic web.

These long tendrils of galaxies spin on the scale of hundreds of millions of light-years. A rotation on such enormous scales has never been seen before according to&nbsp;astronomers at the Leibniz Institute for Astrophysics Potsdam (AIP).

The results published in Nature Astronomy signify that angular momentum can be generated on unprecedented scales.

Such a potential flow is irrotational or curl-free: there is no primordial rotation in the early Universe and angular momentum must be generated as structures form.

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Cosmic filaments are huge bridges of galaxies and dark matter that connect clusters of galaxies to each other. They funnel galaxies towards and into large clusters that sit at their ends.

According to&nbsp;Peng Wang, both an author of the study and&nbsp;astronomer at the AIP,&nbsp;“By mapping the motion of galaxies in these huge cosmic superhighways using the Sloan Digital Sky survey – a survey of hundreds of thousands of galaxies – we found a remarkable property of these filaments: they spin.”&nbsp;

“Despite being thin cylinders – similar in dimension to pencils – hundreds of millions of light-years long, but just a few million light-years in diameter, these fantastic tendrils of matter rotate,” adds Noam Libeskind, initiator of the project at the AIP.

“On these scales the galaxies within them are themselves just specs of dust. They move on helixes or corkscrew-like orbits, circling around the middle of the filament while travelling along with it. Such a spin has never been seen before on such enormous scales, and the implication is that there must be an as yet unknown physical mechanism responsible for torquing these objects.”

How the angular momentum responsible for the rotation is generated in a cosmological context is one of the key unsolved problems of cosmology. In the standard model of structure formation, small overdensities present in the early universe grow via gravitational instability as matter flows from under to overdense regions.

Such a potential flow is irrotational or curl-free: there is no primordial rotation in the early universe. As such any rotation must be generated as structures form. The cosmic web in general and filaments, in particular, are intimately connected with galaxy formation and evolution. They also have a strong effect on galaxy spin, often regulating the direction of how galaxies and their dark matter halos rotate. However, it is not known whether the current understanding of structure formation predicts that filaments themselves, being uncollapsed quasi-linear objects, should spin.

“Motivated by the suggestion from the theorist Dr Mark Neyrinck that filaments may spin, we examined the observed galaxy distribution, looking for filament rotation,” says Noam Libeskind. “It's fantastic to see this confirmation that intergalactic filaments rotate in the real Universe, as well as in computer simulation.”

By using a sophisticated mapping method, the observed galaxy distribution was segmented into filaments. Each filament was approximated by a cylinder. Galaxies within it were divided into two regions on either side of the filament spine (in projection) and the mean redshift difference between the two regions was carefully measured.

The mean redshift difference is a proxy for the velocity difference (the Doppler shift) between galaxies on the receding and approaching side of the filament tube. It can thus measure the filament’s rotation. The study implies that depending on the viewing angle and end point mass, filaments in the universe show a clear signal consistent with rotation.
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Astronomers have discovered the largest rotating structures in the Universe by mapping the motion of galaxies in huge filaments that connect the cosmic web. These long tendrils of galaxies spin on the scale of hundreds of millions of light-years.

Astronomers have discovered the largest rotating structures in the Universe by mapping the motion of galaxies in huge filaments that connect the cosmic web. These long tendrils of galaxies spin on the scale of hundreds of millions of light-years. A rotation on such enormous scales has never been seen before according to astronomers at the Leibniz Institute for Astrophysics Potsdam (AIP). The results published in Nature Astronomy signify that angular momentum can be generated on unprecedented scales. Such a potential flow is irrotational or curl-free: there is no primordial rotation in the early Universe and angular momentum must be generated as structures form. Cosmic filaments are huge bridges of galaxies and dark matter that connect clusters of galaxies to each other. They funnel galaxies towards and into large clusters that sit at their ends. According to Peng Wang, both an author of the study and astronomer at the AIP, “By mapping the motion of galaxies in these huge cosmic superhighways using the Sloan Digital Sky survey – a survey of hundreds of thousands of galaxies – we found a remarkable property of these filaments: they spin.” “Despite being thin cylinders – similar in dimension to pencils – hundreds of millions of light-years long, but just a few million light-years in diameter, these fantastic tendrils of matter rotate,” adds Noam Libeskind, initiator of the project at the AIP. “On these scales the galaxies within them are themselves just specs of dust. They move on helixes or corkscrew-like orbits, circling around the middle of the filament while travelling along with it. Such a spin has never been seen before on such enormous scales, and the implication is that there must be an as yet unknown physical mechanism responsible for torquing these objects.” How the angular momentum responsible for the rotation is generated in a cosmological context is one of the key unsolved problems of cosmology. In the standard model of structure formation, small overdensities present in the early universe grow via gravitational instability as matter flows from under to overdense regions. Such a potential flow is irrotational or curl-free: there is no primordial rotation in the early universe. As such any rotation must be generated as structures form. The cosmic web in general and filaments, in particular, are intimately connected with galaxy formation and evolution. They also have a strong effect on galaxy spin, often regulating the direction of how galaxies and their dark matter halos rotate. However, it is not known whether the current understanding of structure formation predicts that filaments themselves, being uncollapsed quasi-linear objects, should spin. “Motivated by the suggestion from the theorist Dr Mark Neyrinck that filaments may spin, we examined the observed galaxy distribution, looking for filament rotation,” says Noam Libeskind. “It's fantastic to see this confirmation that intergalactic filaments rotate in the real Universe, as well as in computer simulation.” By using a sophisticated mapping method, the observed galaxy distribution was segmented into filaments. Each filament was approximated by a cylinder. Galaxies within it were divided into two regions on either side of the filament spine (in projection) and the mean redshift difference between the two regions was carefully measured. The mean redshift difference is a proxy for the velocity difference (the Doppler shift) between galaxies on the receding and approaching side of the filament tube. It can thus measure the filament’s rotation. The study implies that depending on the viewing angle and end point mass, filaments in the universe show a clear signal consistent with rotation.

Scientists discover largest rotating structures in the universe

Researchers have discovered a huge snowman-shaped star with a unique atmospheric composition.

The enormous white dwarf star is known as WDJ0551+4135 and is thought to have resulted from the merger of two so-called white dwarf stars that often explode as powerful supernovas.

Also read: <a href="https://www.wionews.com/science-tech/dwarf-planet-discovered-in-distant-solar-system-2365">'Dwarf planet' discovered in distant solar system</a>

The study including these findings published Monday in the journal Nature Astronomy.

White dwarf stars are essentially the dead remains of stars like our sun, once they've burned through all of their hydrogen fuel and outer layers.

Also read: <a href="https://www.wionews.com/world/recurring-radio-signals-heard-from-space-after-16-days-280186">Recurring radio signals heard from space after 16 days: Study</a>

Usually, they're small and lightweight but this star is 1.14 times the mass of our sun which is nearly twice the average mass of a white dwarf star.

"This star stood out as something we had never seen before," said Mark Hollands, lead study author and postdoctoral researcher at the University of Warwick's department of physics.

''Initially, these observations didn't make any sense. The only way you can explain it is if it was formed through a merger of two white dwarfs," he added.

Astronomers first spotted the star in data collected by the European Space Agency's Gaia space telescope, launched in 2013.

Researchers have discovered a huge snowman-shaped star with a unique atmospheric composition. The enormous white dwarf star is known as WDJ0551+4135 and is thought to have resulted from the merger of two so-called white dwarf stars that often explode as powerful supernovas.

Researchers have discovered a huge snowman-shaped star with a unique atmospheric composition. The enormous white dwarf star is known as WDJ0551+4135 and is thought to have resulted from the merger of two so-called white dwarf stars that often explode as powerful supernovas. Also read: 'Dwarf planet' discovered in distant solar system The study including these findings published Monday in the journal Nature Astronomy. White dwarf stars are essentially the dead remains of stars like our sun, once they've burned through all of their hydrogen fuel and outer layers. Also read: Recurring radio signals heard from space after 16 days: Study Usually, they're small and lightweight but this star is 1.14 times the mass of our sun which is nearly twice the average mass of a white dwarf star. "This star stood out as something we had never seen before," said Mark Hollands, lead study author and postdoctoral researcher at the University of Warwick's department of physics. ''Initially, these observations didn't make any sense. The only way you can explain it is if it was formed through a merger of two white dwarfs," he added. Astronomers first spotted the star in data collected by the European Space Agency's Gaia space telescope, launched in 2013.

Massive white dwarf star resembling 'space snowman' spotted by scientists

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Scientists discover largest rotating structures in the universe

Massive white dwarf star resembling 'space snowman' spotted by scientists