Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

All-You-Can-Eat at the End of the Universe

12.08.2014

A new model shows how early black holes could have grown to over a billion solar masses

At the ends of the Universe there are black holes with masses equaling billions of our sun. These giant bodies – quasars – feed on interstellar gas, swallowing large quantities of it non-stop.


A small black hole gains mass: Dense cold gas (green) flows toward the center of a stellar cluster (red cross in blue circle) with stars (yellow); the erratic path of the black hole through the gas (black line) is randomized by the surrounding stars

Thus they reveal their existence: The light that is emitted by the gas as it is sucked in and crushed by the black hole's gravity travels for eons across the Universe until it reaches our telescopes.

Looking at the edges of the Universe is therefore looking into the past. These far-off, ancient quasars appear to us in their “baby photos” taken less than a billion years after the Big Bang: monstrous infants in a young Universe.

Normally, a black hole forms when a massive star, weighing tens of solar masses, explodes after its nuclear fuel is spent. Without the nuclear furnace at its core pushing against gravity, the star collapses: Much of the material is flung outwards in a great supernova blast, while the rest falls inward, forming a black hole of only about 10 solar masses.

Since these ancient quasars were first discovered, scientists have wondered what process could lead a small black hole to gorge and fatten to such an extent, so soon after the Big Bang.

In fact, several processes tend to limit how fast a black hole can grow. For example, the gas normally does not fall directly into the black hole, but gets sidetracked into a slowly spiraling flow, trickling in drop by drop. When the gas is finally swallowed by the black hole, the light it emits pushes out against the gas. That light counterbalances gravity, and it slows the flow that feeds the black hole.

So how, indeed, did these ancient quasars grow? Prof. Tal Alexander, Head of the Particle Physics and Astrophysics Department, proposes a solution in a paper written together with Prof. Priyamvada Natarajan of Yale University, which recently appeared in Science.

Their model begins with the formation of a small black hole in the very early Universe. At that time, cosmologists believe, gas streams were cold, dense, and contained much larger amounts of material than the thin gas streams we see in today’s cosmos. The hungry, newborn black hole moved around, changing direction all the time as it was knocked about by other baby stars in its vicinity.

By quickly zigzagging, the black hole continually swept up more and more of the gas into its orbit, pulling the gas directly into it so fast, the gas could not settle into a slow, spiraling motion. The bigger the black hole got, the faster it ate; this growth rate, explains Alexander, rises faster than exponentially.

After around 10 million years – a blink of an eye in cosmic time – the black hole would have filled out to around 10,000 solar masses. From then, the colossal growth rate would have slowed to a somewhat more leisurely pace, but the black hole’s future path would already be set – leading it to eventually weigh in at a billion solar masses or more.

 

Prof. Tal Alexander’s research is supported by the European Research Council.

Yivsam Azgad | Eurek Alert!
Further information:
http://wis-wander.weizmann.ac.il/all-you-can-eat-at-the-end-of-the-universe?press-room-rb#.U-pXYGEcTct

Further reports about: All-You-Can-Eat Big Bang Physics Universe Weizmann black hole gravity quasars solar masses

More articles from Physics and Astronomy:

nachricht Interstellar seeds could create oases of life
28.08.2015 | Harvard-Smithsonian Center for Astrophysics

nachricht Draw out of the predicted interatomic force
28.08.2015 | Hiroshima University

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: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

Im Focus: Fraunhofer IPA develops prototype of intelligent care cart

It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.

Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Interstellar seeds could create oases of life

28.08.2015 | Physics and Astronomy

An ounce of prevention: Research advances on 'scourge' of transplant wards

28.08.2015 | Health and Medicine

Fish Oil-Diet Benefits May be Mediated by Gut Microbes

28.08.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>