The Absolute Cosmos: At 5.25 billion light years away a galaxy survives the black hole’s feast- for now
Black holes are believed to devour much of the surrounding material of their host galaxy putting an end to its life. The process is so intense that it creates a highly energetic object called quasar, which was previously believed to stop the birth of stars.
But now scientists have found a galaxy which is surviving the brutal forces of the black hole by giving birth to new stars at the rate of about hundred Sun sized stars per year.
The galaxy is called CQ4479 and it sits 5.25 billion light years away from us. The galaxy’s core hosts a special type of quasar called cold quasar.
In this type of quasar, the active black hole is still feeding from its host galaxy material but the intense energy of quasar has not destroyed all of the cold gas. As a result stars can keep forming and the galaxy still lives on.
This is for the first time that scientists have studied a cold quasar in such detail. They have directly measured the black hole’s growth, rate of star birth and how much cold gas is left to power the galaxy.
The discovery was made using world’s largest flying observatory SOFIA (Stratospheric Observatory for Infrared Astronomy ). SOFIA is a joint effort by NASA and DLR, the German Aerospace Center.
According to scientists, the new discovery shows that the growth of active black holes does not stop the birth of stars instantaneously, which is not consistent with all the current scientific models.
If the growth continues this way then both the black hole and its surrounding stars would be triple in size before the galaxy actually dies.
Quasars are one of the brightest and most distant objects in our universe. They are extremely difficult to observe as they often outshine everything around them.
They are formed when an active black hole feeds on huge amounts of surrounding material from its host galaxy, creating intense gravitational forces. This material heats up and glows brightly as it spins faster and faster towards the center of the black hole.
Energy produced by a quasar is so much that it outshines everything around it blinding the efforts to observe its host galaxy.
As per modern scientific theories, this energy heats up or expels the cold gas required to form stars, eventually putting a full stop on star birth and galaxy’s growth.
But according to SOFIA observations, there is relatively a short period when star birth in the galaxy can continue while the black hole’s feeding process goes on fuelling the quasar’s immense forces.
SOFIA observations not only enabled scientists to estimate the amount of star formation for the past hundred million years, it also helped scientists to see into the short window of time where the two processes can mutually exist.
This brief window of joint black hole and growth of stars is the early phase in the galaxy’s death, where the galaxy is still surviving the deathly effects of the quasar.
Scientists hope to study more about quasars by using upcoming James Webb Space Telescope, which is scheduled to launch in 2021.
For more information: Dying of the Light: An X-Ray Fading Cold Quasar at z ~ 0.405