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 Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>