Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First black holes kept to a strict diet, study shows

12.08.2009
A new supercomputer simulation designed to track the fate of the universe's first black holes finds that, counter to expectations, they couldn't efficiently gorge themselves on nearby gas. The findings have implications for understanding the formation of galaxies and of the giant black holes that reside in their centers.

"The first stars were much more massive than most stars we see today, upwards of 100 times the mass of our sun," said John Wise, a post-doctoral fellow at NASA's Goddard Space Flight Center in Greenbelt, Md., and one of the study's authors. "For the first time, we were able to simulate in detail what happens to the gas around those stars before and after they form black holes."

The intense radiation and strong outflows from these massive stars caused nearby gas to dissipate. "These stars essentially cleared out most of the gas in their vicinity," Wise said. A fraction of these first stars didn't end their lives in grand supernovae explosions. Instead, they collapsed directly into black holes.

But the black holes were born into a gas-depleted cavity and, with little gas to feed on, they grew very slowly. "During the 200 million years of our simulation, a 100 solar-mass black hole grew by less than one percent of its mass," said Marcelo Alvarez, the study's lead author, at the Kavli Institute for Particle Astrophysics and Cosmology, located at the Department of Energy's SLAC National Accelerator Laboratory in Menlo Park, Calif.

This simulation, which was performed on a supercomputer at SLAC, is the most detailed to date. Starting with data taken from observations of the cosmic background radiation -- a flash of light that occurred 380,000 years after the big bang that presents the earliest view of cosmic structure -- the researchers applied the basic laws that govern the interaction of matter and allowed their model of the early universe to evolve. The complex simulation included hydrodynamics, chemical reactions, the absorption and emission of radiation, and star formation.

In the simulation, cosmic gas slowly coalesced under the force of gravity and eventually formed the first stars. These massive, hot stars burned bright for a short time, emitting so much energy in the form of starlight that they pushed away nearby gas clouds.

These stars could not sustain such a fiery existence for long, and they soon exhausted their internal fuel. One of the stars in the simulation collapsed under its own weight to form a black hole. With only wisps of gas nearby, the black hole was essentially "starved" of matter on which to grow.

Yet, despite its strict diet, the black hole had a dramatic effect on its surroundings. This was revealed through a key aspect of the simulation called radiative feedback, which accounted for the way X-rays emitted by the black hole affected distant gas.

Even on a diet, a black hole produces lots of X-rays. This radiation not only kept nearby gas from falling in, but it heated gas a hundred light-years away to several thousand degrees. Hot gas cannot come together to form new stars. "Even though the black holes aren't growing significantly, their radiation is intense enough to shut off star formation nearby for tens and maybe even hundreds of millions of years," said Alvarez.

The study, which will appear in an upcoming issue of The Astrophysical Journal Letters, shows that early black holes had a surprisingly complex role in shaping the universe.

"I'm thrilled that we now can do calculations that start to capture the most relevant physics, and we can show which ideas work and which don't," said coauthor Tom Abel, also at Kavli. "In the next decade, using calculations like this one, we will settle some of the most important issues related to the role of black holes in the universe."

Francis Reddy | EurekAlert!
Further information:
http://www.nasa.gov

More articles from Physics and Astronomy:

nachricht NASA Protects its super heroes from space weather
17.08.2017 | NASA/Johnson Space Center

nachricht New thruster design increases efficiency for future spaceflight
16.08.2017 | American Institute of Physics

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

Climate change: In their old age, trees still accumulate large quantities of carbon

17.08.2017 | Earth Sciences

Modern genetic sequencing tools give clearer picture of how corals are related

17.08.2017 | Life Sciences

Superconductivity research reveals potential new state of matter

17.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>