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

Authorities arrest 6 individuals in Illinois for attempting to solicit sex from minors.

Six people were arrested in a sex trafficking operation in Illinois targeting…

Unusual element spotted in picture of Trump welcoming French president Macron during his Paris visit for the reopening of Notre-Dame.

Donald Trump awkwardly shook hands with the leader of France during a visit to…

Houston Lawyer Arrested for Fatally Shooting and Cremating Son with Special Needs

A man has been taken into custody and is facing charges of…

“Pope Francis Raises Concerns Over Health as Large Bruise on Chin and Swollen Neck Noticed at Ceremony”

Pope Francis has raised fresh health concerns after being seen with a…

Controversy Erupts as EU Political Party mistakenly shows Falkland Islands as part of Argentina on a map and later acknowledges the error

EU politicians have caused fury after sharing a map depicting the Falkland…

Prince of Wales and President-elect Donald Trump meet at Notre Dame, exchanging warm handshake and embrace at reconstructed Paris cathedral

Prince William and US President-elect Donald Trump shared a warm and firm…

Practitioner sentenced for death of 71-year-old woman in unconventional therapy session

A “DISTURBING” self-proclaimed healer who failed to get help for a dying…

My firsthand experience: Why I believe that Rebekah Vardy is very envious of Coleen Rooney

The ex-husband of Rebekah Vardy has branded her ‘fame hungry’ who will…

Man in Utah Pours Gasoline on Woman and Lights Her on Fire

A Utah man has been jailed after he threw gasoline on a…

A former ambassador predicts that after recent attacks by Syrian rebels, Iran’s weak empire is falling apart, with Putin and Assad as potential targets.

SYRIA is the next domino to fall in Iran’s crumbling empire after…

Russian police conduct large-scale raids to capture and enlist men for Putin’s military following the loss of 45,000 troops in a month

CHILLING footage shows Putin’s minions grabbing terrified civilians off the streets and…

Oti Mabuse kisses husband Marius Lepure as she is the last star evicted from ‘I’m A Celeb’ jungle, final three contestants unveiled

Strictly Come Dancing’s Oti Mabuse was the ninth campmate to be voted…