An ancient pinwheel galaxy is visible in space in the centre of the constellation Delphinus the Dolphin and below the constellation Pegasus the Flying Horse.
For billions of years, the galaxy UGC 11700 has been floating in space like the petals of a flower, regardless of how many natural collisions and mergers have changed the shape of other galaxies in the meantime.
Well, the pinwheel shape of the galaxy ‘UGC 11700’ looks very pleasant, but there is a giant object in its center. At the center of this beautiful galaxy lies one of the most mysterious objects in the universe, a giant black hole.
Black holes are typically four times the mass of the Sun, but their giant relatives can be hundreds of millions and billions of times larger.
Scientists believe that almost every large galaxy has a giant black hole at its center. However, no one yet knows how it got there. Galaxy UGC 11700 can be helpful to find out.
Becky Smithhurst, a junior researcher working on giant black holes at the University of Oxford, says: ‘The ideal galaxies I’m working on have a perfect shape that makes them very beautiful. But these beautiful galaxies will help us unravel the mystery of how these black holes grow and expand.’
Research becomes extremely difficult on an object that is inherently so dirty that even light cannot escape from its core.
However, new techniques to study the effects these giant black holes have on the bodies around them, even the ripples they cause in the fabric of space-time, are giving us new ideas. Providing evidence.
There is no mystery about how black holes form and grow in the traditional way.
Collapsing stars, which run out of fuel to survive, explode in a supernova, all of their matter shrinking into a small area. But due to this, they become so dirty that even light cannot escape from their intense gravity.
The concept of black holes has been around for almost a century now and dates back to famous scientist Albert Einstein’s ‘Theory of General Relativity’.
The general perception is that black holes swallow everything in their path except the super-black ones. He is thought of as a vacuum cleaner in the universe whose nature is to swallow all things. As they swallow things, they grow in size, and with the increase in size comes an increase in appetite.
You’d think it wouldn’t be mysterious then, and that supermassive black holes would be the oldest and hungriest.
In reality, however, black holes do the opposite of their giant reputation. They have surprisingly little ability to swallow anything, even with so many stars around them. In fact, these dead stars grow in size so slowly that they cannot become giants simply by swallowing other objects.
“Suppose stars formed 200 million years after the Big Bang turned into black holes,” says Smithhurst. After they were destroyed, they still had about 13.5 billion years in which these black holes could grow to billions of times the size of the Sun, but this time is too short to grow in size simply by swallowing other objects.
Surprisingly, when the universe was in its early stages after its existence, there were still giant black holes.
Some of the brightest objects in the sky are actually quasars. These are the oldest, supermassive black holes that have lit up the centers of dying galaxies.
Some of these giant black holes have been around since the universe was only 670 million years old and the oldest galaxies were forming.
What is at the center of a black hole is particularly difficult for astronomers observing from afar. But supermassive black holes can be more luminous than a star-filled galaxy, and as they gobble up material around them, they sometimes emit ultraviolet rays.
Black holes have a circular boundary called the ‘event horizon’. For light, energy and matter it is impossible for them to get out of this sphere.
This means that they must have been born in a different way.
Smithhurst tries to go back in time to see how these black holes would have initially grown to their current size.
Their best models suggest that black holes that were born early in the universe and are 1,000 to 100,000 times more massive than the Sun, may have outgrown other black holes. can help happen.
But these data do not match Neumayer’s theory of medium-sized black holes. Black holes of this size cannot possibly form through the death of stars.
Astrophysicists are also considering the possibility that supermassive black holes do not originate directly from dark matter. Dark matter is the mysterious substance that holds galaxies together.
But this dark matter is invisible in light and other rays of the electromagnetic spectrum, and our understanding of it is still incomplete. Physics becomes even more challenging when we combine the mysteries of black holes and dark matter.
