Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Astronomers look back 9 billion years and get a picture of a dying galaxy

Astronomers look back 9 billion years and get a picture of a dying galaxy



An amazing image shows a dying galaxy emitting 10,000 suns of gas each year after a giant collision – weakening its ability to form stars

  • Researchers observed the galaxy when the universe was 4.5 billion years old
  • The ejected gas is probably the result of an earlier merger with another galaxy
  • This gas leak caused the galaxy to stop producing new stars

A sensational image of a dying galaxy – emitting gas worth 10,000 suns each year due to a major collision – was taken by an international team of astronomers.

A new study, led by the University of Durham, looks at nine billion years in the past in search of evidence that galaxy mergers in the early universe could stop star formation.

These mergers force gas to flow out of the galaxy and weaken its ability to form new stars, effectively marking the end of its life as an active body.

The team found that a huge amount of star-forming gas was released into the intergalactic environment by the merging of two galaxies.

The researchers say that this event, along with a large amount of star formation in the nuclear regions of the newly united galaxy – called ID2299 – will eventually deprive the single fused body of the fuel needed to form new stars.

This would stop the formation of stars for several hundred million years, effectively stopping the galaxy from developing.

This artist's impression of ID2299 shows the galaxy, a product of a galactic collision, and part of its gas ejected by

This artist’s impression of ID2299 shows the galaxy, a product of a galactic collision, and part of its gas ejected from a “tidal tail” as a result of the merger.

Due to the time it took for light from ID2299 to reach Earth, researchers were able to see the galaxy as it would have looked nine billion years ago when it was in the late stages of its fusion.

This is a time when the universe was only 4.5 billion years old and was in its most active phase as a “young adult” – compared to human life.

Using the European Southern Observatory’s Northern Mill Observatory (ALMA) telescope in northern Chile, researchers saw that it dumps about half of its total gas tank around the galaxy at a rate equivalent to 10,000 suns a year. .

Lead author Dr Anagrazia Puglisi of the University of Durham’s Center for Extragalactic Astronomy said: “We still don’t know the exact processes behind the exclusion of star formation in massive galaxies.

“Star feedback wind or active black holes are considered to be the main responsible for gas discharge and growth suppression.

“Our study provides evidence that the gas emitted by ID2299 was probably ejected due to the merger between two gas-rich galaxies.

“The gravitational interaction between two galaxies can thus provide a sufficient angular momentum to expel some of the gas in the vicinity of the galaxy.

“This suggests that mergers may also change the future evolution of a galaxy by limiting its ability to form stars for millions of years and deserve more study when it comes to the factors that limit galaxy growth.”

The researchers were able to rule out star formation and the galaxy’s active black hole as the cause of this ejection by comparing their measurements with previous studies and simulations and measuring the physical properties of the emitted gas.

The rate at which gas is ejected from ID2299 is too high to be caused by energy from a black hole or stellar burst, as seen in previous studies.

The researchers say the simulations suggest that no black holes can emit as much cold gas from the galaxy as seen expelled from ID2299.

The excitation of the exhaust gas is also not compatible with the wind generated by a black hole or the birth of new stars.

Using the European Southern Observatory (ALMA) telescope at the European Southern Observatory in northern Chile, researchers saw it dump about half of its total gas tank around the galaxy.

Using the European Southern Observatory’s northern millimeter Atacama Telescope (ALMA), researchers have seen it dump about half of its total gas tank around the galaxy.

Co-author Dr Emanuele Dadi of CEA-Saclay said: “This galaxy is witnessing a truly extreme event.

“It was probably captured during an important physical phase for the evolution of the galaxy, which occurs in a relatively short period of time. We had to look at over 100 galaxies with ALMA to find it.

Co-author Dr Jeremy Fensch of the Center for Scientific Astrophysics in Lyon added: “The study of this single case revealed that this type of event is not uncommon and that many galaxies have suffered from this ‘gravitational gas removal’, including misinterpreted pasts. observations.

“This can have huge implications for our understanding of what actually shapes the evolution of galaxies.”

Researchers now hope to obtain higher-resolution images of ID2299 and other distant galaxy mergers and perform computer simulations to further understand the effect that galaxy mergers have on the life cycle of galaxies.

The findings are published in the journal Nature Astronomy.

WHAT IS ALMA?

Deep in the Chilean desert, the large millimeter massif of Atacama or ALMA is located in one of the driest places on Earth.

At an altitude of 16,400 feet, approximately half the height of a jumbo jet and almost four times the height of Ben Nevis, workers had to carry oxygen tanks to complete its construction.

Launched in March 2013, it is the most powerful ground-based telescope in the world.

It is also the tallest on the planet and with almost 1 billion pounds ($ 1.2 billion), one of the most expensive of its kind.

Deep in the Chilean desert, the large millimeter massif of Atacama or ALMA is located in one of the driest places on Earth.  Launched in March 2013, it is the most powerful ground-based telescope in the world

Deep in the Chilean desert, the large millimeter massif of Atacama or ALMA is located in one of the driest places on Earth. Launched in March 2013, it is the most powerful ground-based telescope in the world

Advertising




Source link