Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Black holes form first, galaxies follow: new quasar study

09.01.2003


A study at Ohio State University has uncovered more evidence that black holes form before the galaxies that contain them.


Artist’s rendering of a black hole in a globular cluster. Photo courtesy NASA and G. Bacon, Space Telescope Science Institute.


Marianne Vestergaard



The finding could help resolve a long-standing debate, said Marianne Vestergaard, a postdoctoral fellow in astronomy at Ohio State.

Vestergaard came to this conclusion when she studied a collection of very energetic, active galaxies known as quasars as they appeared some 12 billion years ago, when the universe was only one billion years old. While the quasars were obviously young -- they contained large stellar nurseries in which new stars were forming -- each also contained a very massive, fully formed black hole.


More and more, black holes are being found at the center of galaxies. As the close relationship between black holes and galaxies has emerged, astronomers have debated which of the two came first.

One model holds that mass builds up at the center of galaxies, eventually collapsing so black holes can form. Another holds the opposite -- that black holes exist first, and their immense gravity draws gas, dust, and stars together, causing galaxies to form.

Looking at this evidence, I have to think that black holes start forming before galaxies do, or form at a much faster rate, or both, Vestergaard said. She described her study January 8 at the American Astronomical Society meeting in Seattle.

One year ago, Vestergaard announced that she had developed a new method for estimating the mass of very distant black holes, ones that existed far in the past. The method involves comparing the spectrum of light emitted by the quasars that host the black holes to spectra from quasars existing today.

Astronomers consider a galaxy active when it emits much more energy from its nucleus than can be accounted for by its stars alone. This radiation is detected at wavelengths that span from radio waves to X-rays, Vestergaard explained.

Quasars are the most energetic of the active galaxies, from which all the energy spills out of a very small region at the center, equal to about one-millionth of the diameter of the total galaxy. It is in these central regions that black holes reside.

For this latest study, Vestergaard used her method to examine a special set of distant quasars. Part of her data came from the Sloan Digital Sky Survey, a collaborative project that maps the universe from Apache Point Observatory in New Mexico. She compared the spectra from those quasars to other quasars that are closer to Earth, including ones documented by the Bright Quasar Survey.

In the several hundred quasars she studied, a pattern emerged: even the smallest, most quiescent of these active galaxies contained a massive black hole, on the order of 100 million times more massive than our sun.

Theoretically, the black holes should have taken a long time to grow that big, if they started out as small seed black holes and grew by accretion alone; yet, their host galaxies showed ample signs of youth, such as intense star formation, copious amounts of molecular gas and significant dust production.

This information could help astronomers better understand active galaxies, as well as more typical inactive galaxies such as our own.

All these issues are intertwined -- the powering of the central engine of an active galaxy, the forming of black holes, the forming of galaxies, she said.

She added that future developments in this area will depend on KRONOS, a satellite proposed to NASA by Bradley Peterson, professor of astronomy at Ohio State, and his partners from around the world. KRONOS will be able to image material spiraling into black holes with a resolution 10,000 times finer than now possible with the Hubble Space Telescope.

For instance, how fast do black holes grow? Do they grow only by accumulating matter from around themselves, or do they also need some cataclysmic trigger event, such as when two galaxies collide? We need deep surveys of the universe to answer these questions, Vestergaard said.

Other pieces of the puzzle will come from researchers such as Ohio State graduate student Adam Steed, who is working with astronomy professor David Weinberg to model black hole growth.

If we could construct a complete model of what happens to a black hole over its lifetime, we could look at real black holes from different points in the past, and see whether our model is consistent, Vestergaard said. That would be really exciting, and we would understand more about what is happening in the universe today.

Vestergaard remains optimistic that astronomers can conquer these hurdles in the near future.

I never thought we would come to a day in my lifetime when we could measure the mass of such distant black holes, she said. But here we are.


Marianne Vestergaard, (614) 292-5807; Vestergaard.1@osu.edu
Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu

Marianne Vestergaard | EurekAlert!
Further information:
http://www.osu.edu/researchnews/archive/bhfirst.htm

More articles from Physics and Astronomy:

nachricht A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>