Supermassive black holes discovered in dying distant galaxies: Study

Supermassive black holes may have the ability to “suppress” star formation in their galaxies, according to a new study that found many supermassive black holes very early in the life of their local universes. ta.

An international team of astronomers has combined data from some of the most powerful telescopes on Earth to piece together an idea of ​​how galaxies with little to no star formation can be. Concerning black holes, consider radio emission from galaxies more than 10 billion light-years away for the first time in years.

The study, published in the Journal of Astrophysics in April, compared data from condensed galaxies with those of star-forming galaxies, and found that among the older galaxies, the Non-stellar galaxies are more likely to have a supermassive black hole lurking at their center.

In the known universe, there are countless galaxies in different stages of development.

Many of the massive elliptical galaxies in our local universe – which refers to a region around the solar system with a radius of about 1 billion light-years – are relatively stagnant, with little to no star formation.

Modeling in previous work has suggested that these galaxies experienced a period of intense star formation early in their lives, followed by an abrupt slowdown.

But why are some galaxies still producing stars while others have stalled?

“It is not well understood what physical processes cause the rapid extinction and prevent further star-forming activity,” the study states.

One hypothesis for preventing star formation is that radiation pouring out of an active galactic nucleus could interfere with the formation of new stars in that particular galaxy.

The active galactic nucleus (AGN) is a small, central spot in a galaxy that is significantly more luminous and radiating than anything else in the galaxy, sometimes so bright that it outstrips the entire galaxy. galaxy set.

AGNs are thought to surround a supermassive black hole, with radiation being a byproduct of matter corroding that black hole so close.

However, while it has previously been hypothesized that black holes may be involved in slowing down star formation in galaxies, many questions remain.

In this study, the researchers wanted to deepen the theory by looking at a wide range of galaxies at once, including those fainter and more distant, that may not have been included in previous studies. this.

Since it takes a long time for light from distant galaxies to reach us, what we see when we look in the sky are snapshots of those galaxies that once looked like millions, even billions of years ago.

The more ancient and distant the galaxy, the harder it is to study.

Because signals from individual galaxies are too faint to be identified, in this new study, researchers superimposed X-ray and radio images of galaxies to help filter out the noise and better understand the average signal from these galaxies.

The researchers selected the galaxies for review using the latest data from the Cosmic Evolution Survey (COSMOS), an astronomical survey that focuses on a specific field of the universe ant, comprising more than two million galaxies, to study the formation and evolution of galaxies.

The team led by researchers in Japan looked specifically at galaxies 9.5 – 12.5 billion light-years away.

What the researchers found is that the X-ray luminance of stagnant galaxies at least 12 billion light-years away is higher than that of star-forming galaxies at the same mass and distance. But the X-ray signals and radio emission of these condensed galaxies cannot be explained by the number of their stars, suggesting that this high luminosity is coming from an AGN, and thus a hole. Super big black.

Condensation galaxies are also more common in galaxy clusters or other dense parts of the universe than in the general space field.

The study also shows a tendency for condensing galaxies to be brighter in luminosity than weaker star-forming galaxies in galaxies younger and closer to Earth than in galaxies much farther away.

The researchers hypothesize that this may be because other factors are driving star formation in these closer galaxies rather than being driven largely by the presence of a black hole. super big.

“Our work hints at the evolving role of the AGN feedback for higher redshift galactic quenching and future observations of [stagnant galaxies] may shed more light on detailed physics,” the study stated in its conclusion. Redshift is a term in astronomy that refers to the distance of an object in space, with a higher redshift meaning it is further away from us.

The researchers note that there are still aspects of the data that cannot be explained purely by AGN, and that more research is needed into how and why black holes might be involved in preventing formation. become a star.

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