Astronomers discover five rare galaxies 'interacting with each other'

A group of five ‘dwarf’ galaxies that are ‘interacting with each other’ have been discovered by astronomers about 117 million light years away from Earth

Dwarf galaxies contain a few billion stars, whereas standard galaxies have hundreds of billions, giving them low mass and luminosity.

The newly found galaxies are blue, gas-rich and actively forming new stars.

They were given the designations D1 to D5, with D3 and D4 displaying indications of mutual tidal interactions, which implies that their respective gravitational forces are tugging on each other and altering the shapes of the galaxies. 

D3 and D4 have formed ‘tidal tails,’ which are slim, elongated areas consisting of stars and interstellar gas that extend outwards and away from the location where the galaxies are colliding.

It is highly uncommon for dwarf galaxies to appear in groups as studies suggest less than five percent of dwarf galaxies are neighbors with another. 

Thus, there is less an a 0.004 percent chance that a dwarf galaxy would be so close to four others.

Despite those incredibly low odds, ‘We have identified a distinct group of dwarf galaxies, with all five members aligned along a straight line in the celestial plane and three sharing a common rotational direction,’ the researchers wrote in their report.

The discovery of this exceedingly unique group is forcing scientists to question the prevailing model of our universe, but should also help scientists better understand how dwarf galaxies form and evolve. 

The group of dwarf galaxies, designated D1 through D5, is exceedingly rare

A team of researchers led by the Yonsei University in Seoul, South Korea, discovered the dwarf galaxy group by analyzing data from various astronomical surveys that continually scan space looking for new discoveries.

These surveys use telescopes to observe millions of celestial objects in deep space, creating enormous, highly detailed maps of the universe.

The researchers’ analysis revealed the presence of the group of dwarf galaxies, isolated together in deep space.

They estimated the total dynamical mass – or the mass of an object inferred from its movement relative to other objects – of the group to be roughly 60.2 billion times the mass of our sun, the study found. 

Their individual masses vary widely. The largest group member, galaxy D2, has a stellar mass of approximately 275 million solar masses. 

The least massive, D4, has a stellar mass of only 14.7 million solar masses.

For comparison, our galaxy – the Milky Way – has a stellar mass of about 1.5 trillion solar masses, according to NASA.

The researchers published their findings in The Astrophysical Journal Letters on November 19. 

They were designated from D1 to D5, and two of them – D3 and D4 – are showing signs of mutual tidal interactions , which means their respective gravitational forces are pulling on each other and distorting the galaxies’ shapes 

Dwarf galaxies only contain a few billion stars , whereas standard galaxies have hundreds of billions. This is irregular dwarf galaxy NGC 6822 - which is not part of the newly found group

Dwarf galaxies only contain a few billion stars , whereas standard galaxies have hundreds of billions. This is irregular dwarf galaxy NGC 6822 – which is not part of the newly found group

To find five dwarf galaxies grouped together in a near-straight line, with most of them rotating in the same direction, is so unusual that it challenges predictions made by the prevailing model of how the universe formed.

That model, called Lambda cold dark matter (LCDM), suggests that dark matter causes disordered groupings of galaxies.

By that logic, galaxies are not expected to have a preferred alignment. The five dwarf galaxies, however, are aligned in a configuration that is ‘not frequently seen in CDM simulations,’ study lead author Sanjaya Paudel of Yonsei University in South Korea told Space.com.

What’s more, the fact that three of the five galaxies share the same direction of rotation – as shown by DESI observations – suggests that they formed from the same cloud of gas. This further contradicts the LCDM model. 

‘Why do they have the same rotation?’ said Paudel. ‘They must have a connection with each other – that would be a very strong question that cannot be explained by the ΛCDM model.’ 

As of now, this discovery yields more questions than answers. But future studies could soon confirm whether the galaxies’ unlikely configuration is a chance projection or a real physical arrangement, the researchers stated in their report.

Additionally, studying these five dwarf galaxies could help scientists better understand how such objects form and evolve.

Astronomers believe dwarf galaxies were created by gravitational forces in the early stages of the creation of larger galaxies, or as a result of collisions between galaxies that eject streams of material out into space. 

Dwarf galaxies are thought to be important for important in scientists’ understanding of the overall evolution of galaxies, according to the European Space Agency. 

Those that lack a defined shape – known as ‘irregular’ dwarf galaxies – are considered similar to the earliest galaxies that populated the Universe. Thus, studying them offers a glimpse into ancient cosmological history.  

More than 20 known dwarf galaxies orbit the Milky Way. But they are locationally and gravitationally separate from each other, not grouped together. 

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like

Anders Breivik, the Neo-Nazi murderer who asked for early release 13 years post island massacre where 77 people died, will not be set free – court acknowledged ‘positive’ changes.

Anders Behring Breivik, a neo-Nazi killer who sought parole just 13 years…

Florida Teacher Found Naked in School Where He Was Not Employed

A teacher at a Florida charter upper level school was found naked…

Chancellor Rachel Reeves said that more tax increases are needed to stabilize the country’s finances

TAXES will have to be hiked further to help stabilise the public…

Police officer throws delivery worker off bridge in Brazil during traffic stop: A shocking incident

A police officer was caught on video throwing a man off a…

Search is ongoing for shooter in mask who killed insurance company CEO named Brian Thompson

Investigators are going through clues discovered at the location of the deadly…

Uncovering the Surprising Story of a Quiet British Market Town Turned Hotspot for Suspicious Offshore Money: How £146m Has Been Funneled into Property Purchases in this Seemingly Sleepy Location

With its cosy pubs, medieval parish church and quiet high street boasting…

Gunman deceives principal before shooting two children at elementary school

A SICK gunman shot two kindergarteners in a targeted attack because of…

Unnerving Inscription Discovered on Bullets Linked to UnitedHealthcare CEO Brian Thompson’s Assassination

THE assassin who killed UnitedHealthcare CEO Brian Thompson left a message on…

Anticipating Future Resignations: Trump’s Cabinet Faces Growing Turmoil, Notes Andrew Neil

The new administration has not even begun, and Donald Trump has not…

Hannah Kobayashi, a Hawaiian beauty, is believed to be a victim of a possible scam marriage.

Missing photographer Hannah Kobayashi may have fallen victim to a marriage scam…

A 19-year-old student made a frantic phone call from an unfamiliar number before disappearing during a walk 3 weeks ago.

A STUDENT made a desperate call from an unknown number before she…

President Yoon: The American Pie-singing anti-communist who caused chaos in South Korea with a martial law decree

PRESIDENT Yoon’s crumbling reputation could have taken a final blow after declaring…