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

Revealing Assad’s brutalities: Horrific scenes of tortured bodies and piles of clothing found at prison likened to a slaughterhouse, guarded by cruel officials reminiscent of Hitler.

REBELS have uncovered tortured bodies, piles of clothes and various equipment used…

‘Ruth Langsford unexpectedly mentions ex-husband Eamonn Holmes in discussion as Loose Women goes to commercial break during divorce topic’

Ruth Langsford caused Loose Women to suddenly cut to a break when…

“Luigi Mangione, CEO Accused of Murder, Shared Frustrations about Sex and Dating with Roommate”

The man accused of killing UnitedHealthcare’s chief executive was yearning for a…

Susan Smith, a convicted murderer, likely to face disappointment regarding her aspirations to appear on Dancing With The Stars.

Thirty years after Susan Smith drove her car into a lake with…

Be cautious of Christmas light show scheme demanding payment from attendees at popular festive destination

CHRISTMAS revelers have been warned over a light show scam that left…

Discovered: The Last Social Media Post of a Schoolgirl Before Being Stabbed in the Neck in Dispute Over a Teddy Bear – Jury Sees CCTV Footage of the Attack at Croydon Bus Stop

Before she was tragically stabbed in the neck, a 15-year-old schoolgirl took…

26-year-old Luigi Mangione apprehended at McDonald’s for the murder of CEO Brian Thompson

LUIGI Mangione has been charged with the murder of UnitedHealthcare CEO Brian…

Image: Mother, aged 41, fatally attacked by ‘her pet dog’ at apartment in Aberdeen while her grieving relatives honor her

Police have released the name of a mother who was mauled to…

“Renowned Doctor creates revolutionary ‘scientific sandwich’ proven to cure hangovers instantly”

Tis the season many of us start overindulging in a few too…

Touching act by 5-year-old kindergartener injured in school shooting, sustaining ‘pierced organs’

A KINDERGARTENER injured in a school shooting made a heartbreaking gesture to…

The Identity of Jane Rimmer: Victim of Bradley Robert Edwards, also known as the Claremont Killer

JANE Rimmer was a childcare assistant who became the first known victim…

Luigi Mangione, CEO linked to violence, praised Unabomber and advocated for violence before alleged act against Brian Thompson.

THE suspected assassin of the UnitedHealthcare CEO praised the deranged Unabomber months…