Supersized black holes at the center of galaxies do not only destroy stars but also create them, a group of astronomers has discovered.
These supermassive black holes, lurking at the center of galaxies with masses of more than one billion suns, emerged when a giant star collapsed. Nothing, including stars, escapes from it.
It has been speculated, however, that these stellar black holes could give birth to stars but there was no evidence to support it until recently.
A team of astrophysicists using the Very Large Telescope in Chile has found evidence of stars being born from an outflow of gases after the two galaxies, each with a supermassive black hole at their core, collided. These galaxies are located 600 million light-years away from the Earth.
New Stars Are Born
Typically, stars are born out of the build up of gas and dust.
The immense gravitational force of these supermassive black holes, which could pull stars apart, can produce an outflow of gases used as a rich source of gas and dust to form new stars.
The gases, spinning around the black hole, exist in an accretion disk where they are worked up in extremely high temperatures before being jettisoned to space. Some of the materials, the astronomers said, are thrown out into space altogether.
The newborn stars lie at a safe distance, some 100 light-years away, from the supermassive black hole. Others even lie as far as 5,000 to 10,000 light-years away.
Some of these stars may eventually return to the supersized black hole while others might continue their journey and settle on the edges of the galaxy or even beyond.
The newly found stars are about 10 times bigger than the sun, astrophysicist Robert Maiolino. He is the lead author of the paper published in the journal Nature on March 27.
These stars, which could be 40 or 50 times the size of the sun, are still in their infancy stage. Reckoned from a universal time scale, the new stars are still in their tens of million years old.
Reshaping The Theory Of Galactic Formation
The recent discovery could change the understanding of how galaxies are formed.
Spiral galaxies are known to have a lump of stars at their core and a halo made of dispersed cloud of stars while the elliptical ones are spherical. Then the creation of new stars from the outflow of gases could shed a light why certain galaxies are shaped the way they are.
"This could change quite drastically our understanding of galaxy formation evolution," Maiolino said.
The discovery could also help explain why heavy elements, known as an interstellar medium, exist in between galaxies.
The lead author said they are now looking for other galactic centers where a similar process of star formation occurs.