Astronomers observe fast growing primitive black holes

March 17, 2010

Quasars are active and very powerful black holes at the centre of distant galaxies. The black holes are extremely massive weighing between 100 million and 10 billion solar masses and rotating around the super massive black hole is a disc of gas and dust. The inner ring of the disc moves faster than the outer rings. The movement causes the material in the rings to rub against each other, heating it and causing it to emit light. Near to the black hole it becomes so hot that X-ray radiation is emitted, farther out ultraviolet light is emitted, then visible light and farthest out infrared radiation. Even though the radiation is coming from a very small area the size of our solar system, it is so powerful that it can be seen across the universe.

Enormous black holes

"Quasars are a very early stage of galaxies, a sort of baby galaxies", explains Marianne Vestergaard, astrophysicist at the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen. "Most galaxies have a massive black hole with a mass of over a million solar masses, but quasars are different. Their black holes are active and growing. The gravity of the black hole gradually pulls the surrounding material of gas and dust into the black hole, which consequently slowly grows heavier and larger. The disc of gas and dust is also resupplied with material from the galaxy, so the quasar can grow into some of the most massive objects known in the universe, second to galaxies", explains Marianne Vestergaard.

But why do quasars always resemble each other? The researchers had wondered about this and their new research revealed something else. Together with colleagues from the US and Germany she observed 21 quasars in the distant universe, when it was only 800 million years old (it is currently 13.7 billion years old).

"With our new observations we could see that many of them had lots of hot dust, but two quasars did not - they had no sign of hot dust, so we wondered why", explains Marianne Vestergaard.

Witnesses to the growth of the first black holes

In two of the most distant quasars there are indications that they reside in very young galaxy systems with less dust, where the black hole is growing rapidly. For these distant black holes, the researchers see that the quasars without hot dust have small black holes, which devour gas at great haste, while the quasars with heavier black holes have more hot dust at the centre. A possible explanation is that the black holes grow in step with the formation of stars in the galaxy. An increasing number of stars give an increasing amount of dust.

The farther away in the universe one looks, the farther back in time one sees and astronomers are hunting for galaxies where they can study the formation of the first dust in the universe. Dust has a great impact on how and how early in the history of the universe stars were formed.

"I appears we have found what are likely primitive first-generation quasars, that are born in a dust-free medium shortly after Big Bang and are now seen at somewhat stages of evolution. With these quasars showing both rapid growth in both the black hole and the amount of dust, we may have found the young galaxy systems we have long been looking for", explains Marianne Vestergaard and adds that "it is fantastic that we are witness to this building up of black holes and the amount of heavier elements in the form of dust".
Marianne Vestergaard, astrophysicist,
Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen
+45 3532-5909,

University of Copenhagen

Related Black Hole Articles from Brightsurf:

Black hole or no black hole: On the outcome of neutron star collisions
A new study lead by GSI scientists and international colleagues investigates black-hole formation in neutron star mergers.

The black hole always chirps twice: New clues deciphering the shape of black holes
A team of gravitational-wave scientists led by the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) reveal that when two black holes collide and merge, the remnant black hole 'chirps' not once, but multiple times, emitting gravitational waves--intense ripples in the fabric space and time--that inform us about its shape.

Wobbling shadow of the M87 black hole
New analysis from the Event Horizon Telescope (EHT) Collaboration reveals the behavior of the supermassive black hole in the center of the M87 galaxy across multiple years, indicating the crescent-like shadow feature appears to be wobbling.

How to have a blast like a black hole
Scientists at Osaka University have created magnetized-plasma conditions similar to those near a black hole using very intense laser pulses.

Black hole collision may have exploded with light
Astronomers have seen what appears to the first light ever detected from a black hole merger.

Black hole's heart still beating
The first confirmed heartbeat of a supermassive black hole is still going strong more than ten years after first being observed.

Black hole team discovers path to razor-sharp black hole images
A team of researchers have published new calculations that predict a striking and intricate substructure within black hole images from extreme gravitational light bending.

Planets around a black hole?
Theoreticians in two different fields defied the common knowledge that planets orbit stars like the Sun.

Black hole mergers: Cooking with gas
Gravitational wave detectors are finding black hole mergers in the universe at the rate of one per week.

Going against the flow around a supermassive black hole
At the center of a galaxy called NGC 1068, a supermassive black hole hides within a thick doughnut-shaped cloud of dust and gas.

Read More: Black Hole News and Black Hole Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to