Astronomers put forward new theory on size of black holes

Gas-guzzling black holes eat 2-courses at a time

2012-03-26

(Press-News.org) Astronomers have put forward a new theory about why black holes become so hugely massive – claiming some of them have no 'table manners', and tip their 'food' directly into their mouths, eating more than one course simultaneously.

Researchers from the UK and Australia investigated how some black holes grow so fast that they are billions of times heavier than the sun.

The team from the University of Leicester (UK) and Monash University in Australia sought to establish how black holes got so big so fast. Their research is due to published in the Monthly Notices of the Royal Astronomical Society.

The research was funded by the UK Science and Technology Facilities Council.

Professor Andrew King from the Department of Physics and Astronomy, University of Leicester, said: "Almost every galaxy has an enormously massive black hole in its centre. Our own galaxy, the Milky Way, has one about four million times heavier than the sun. But some galaxies have black holes a thousand times heavier still. We know they grew very quickly after the Big Bang.''

"These hugely massive black holes were already full--grown when the universe was very young, less than a tenth of its present age."

Black holes grow by sucking in gas. This forms a disc around the hole and spirals in, but usually so slowly that the holes could not have grown to these huge masses in the entire age of the universe. `We needed a faster mechanism,' says Chris Nixon, also at Leicester, "so we wondered what would happen if gas came in from different directions."

Nixon, King and their colleague Daniel Price in Australia made a computer simulation of two gas discs orbiting a black hole at different angles. After a short time the discs spread and collide, and large amounts of gas fall into the hole. According to their calculations black holes can grow 1,000 times faster when this happens.

"If two guys ride motorbikes on a Wall of Death and they collide, they lose the centrifugal force holding them to the walls and fall," says King. The same thing happens to the gas in these discs, and it falls in towards the hole.

This may explain how these black holes got so big so fast. "We don't know exactly how gas flows inside galaxies in the early universe," said King, "but I think it is very promising that if the flows are chaotic it is very easy for the black hole to feed."

The two biggest black holes ever discovered are each about ten billion times bigger than the Sun.

###Note to newsdesk: For more information, contact Professor Andrew King on ark@astro.le.ac.uk

Movie simulations can be found here: http://www.astro.le.ac.uk/~cjn12/tilt.shtml

Figures are available in the original paper: http://www.astro.le.ac.uk/~cjn12/papers/twist.pdf

STFC The Science and Technology Facilities Council is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security.

The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar.

STFC operates or hosts world class experimental facilities including:

in the UK; ISIS pulsed neutron source, the Central Laser Facility, and LOFAR. STFC is also the majority shareholder in Diamond Light Source Ltd. overseas; telescopes on La Palma and Hawaii

It enables UK researchers to access leading international science facilities by funding membership of international bodies including European Laboratory for Particle Physics (CERN), the Institut Laue Langevin (ILL), European Synchrotron Radiation Facility (ESRF) and the European Southern Observatory (ESO).

STFC also has an extensive public outreach and engagement programme. It is using its world leading research to inspire and enthuse schools and the general public about the impact and benefits that science can have on society.

STFC is one of seven publicly-funded research councils. It is an independent, non-departmental public body of the Department for Business, Innovation and Skills (BIS).

Follow us on Twitter @STFC_Matters

ELSE PRESS RELEASES FROM THIS DATE:

Swarming and transporting

2012-03-26

The orange-colored vehicle begins moving with a quiet whirr. Soon afterwards the next shuttles begin to move, and before long there are dozens of mini-transporters rolling around in the hall. As if by magic, they head for the high-rack storage shelves or spin around their own axis. But the Multishuttle Moves® – is the name given to these driverless transport vehicles – are not performing some robots' ballet. They are moving around in the service of science. At the Fraunhofer Institute for Material Flow and Logistics IML in Dortmund, Germany, researchers are working to harness ...

Who knew? Fruit flies get kidney stones too, may hold key to treatment for humans

2012-03-26

ROCHESTER, Minn. -- Research on kidney stones in fruit flies may hold the key to developing a treatment that could someday stop the formation of kidney stones in humans, a team from Mayo Clinic and the University of Glasgow found. They recently presented their findings at the Genetics Society of America annual meeting. "The kidney tubule of a fruit fly is easy to study because it is transparent and accessible," says physiologist Michael F. Romero, Ph.D., of Mayo Clinic in Rochester, Minn. He said researchers are now able to see new stones at the moment of formation. "More ...

Expectations, exhaustion can lead mothers to post-adoption stress

2012-03-26

WEST LAFAYETTE, Ind. - Fatigue and unrealistic expectations of parenthood may help contribute to post-adoption depression in women, according to a Purdue University study. "Feeling tired was by far the largest predictor of depression in mothers who adopted," said Karen J. Foli, an assistant professor of nursing who studied factors that could predict depression in adoptive mothers. "We didn't expect to see this, and we aren't sure if the fatigue is a symptom of the depression or if it is the parenting experience that is the source of the fatigue. It also may be reflective ...

Brain insulin resistance contributes to cognitive decline in Alzheimer's disease

2012-03-26

PHILADELPHIA – Insulin resistance in the brain precedes and contributes to cognitive decline above and beyond other known causes of Alzheimer's disease, according to a new study by researchers from the Perelman School of Medicine at the University of Pennsylvania. Insulin is an important hormone in many bodily functions, including the health of brain cells. The team identified extensive abnormalities in the activity of two major signaling pathways for insulin and insulin-like growth factor in non-diabetic people with Alzheimer's disease. These pathways could be targeted ...

Research sheds new light on extra help for smokers trying to quit

2012-03-26

A major research trial to test whether extra support for smokers calling an NHS quitline - on top of what is already offered by the service - has found the additional help does not improve success rates for quitting the habit. The pilot scheme offered smokers additional help in the form of free nicotine patches and extra telephone counselling from the English National Quitline. The Department of Health and UK Centre for Tobacco Control Studies (UKCTCS)-funded study led by The University of Nottingham's UK Centre for Tobacco Control Studies has just been published in the ...

Non-narcotic pain medication is safe and effective after sinus surgery

2012-03-26

MAYWOOD, Il. -- Patients who have undergone sinus surgery can safely take an alternative pain medication that does not cause the side effects of narcotics such as fentanyl and Vicodin, a Loyola University Health System study has found. The alternative medication is ketorolac (brand name, Toradol). It is in the same class of nonsteroidal anti-inflammatory drugs as Advil and Aleve. Ketorolac does not cause the side effects that narcotic drugs cause, such as itching, nausea, vomiting, constipation and drowsiness, said Kevin Welch, MD, corresponding author of the study, published ...

Identifying acute myeloid leukemia gene mutations may indicate risk, best treatment

2012-03-26

TAMPA, Fla. – An international group of researchers, including those from Moffitt Cancer Center in Tampa, Fla., have published a paper in the March 14 issue of the New England Journal of Medicine reviewing the results of a study that analyzed mutations in 18 genes of 398 patients who had acute myeloid leukemia (AML). They found that several mutated genes predicted improved outcomes when patients with certain gene mutations were given high-dose induction chemotherapy. Their findings suggest that mutational profiling could potentially be used for both risk stratification ...

Marine forensics expert Richard Woytowich seeks to vindicate Titanic survivors' account

2012-03-26

Brooklyn, NY -- On the eve of the 100th anniversary of the Titanic's sinking, marine forensics expert Richard Woytowich will present a paper re-interpreting the statements made by survivors at the 1912 official inquiries into the disaster. Woytowich, a professor of computer engineering technology at New York City College of Technology (City Tech), will take into account what engineers and other technologists now know about how the ill-fated passenger liner broke apart on April 15, 1912. He will be presenting his research on April 4, 8 a.m., at the International Marine ...

A new test might facilitate diagnosis and drug development for Alzheimer's disease

2012-03-26

An international team of researchers have developed a new method for measurement of aggregated beta-amyloid – a protein complex believed to cause major nerve cell damage and dysfunction in Alzheimer's disease. The new method might facilitate diagnosis and detection as well as development of drugs directed against aggregated beta-amyloid. Alzheimer's disease (AD) is the most common cause of memory decline and dementia. According to the Alzheimer World Report 2011, today around 36 million people suffer from Dementia (around 20 - 25 million are Alzheimer's patients). These ...

New ORNL tool developed to assess global freshwater stress

2012-03-26

A new method to make better use of vast amounts of data related to global geography, population and climate may help determine the relative importance of population increases vs. climate change. While several recent studies suggest that much of the world is likely to experience freshwater shortages as the population increases and temperatures rise, determining the relative impact of each has been difficult. An Oak Ridge National Laboratory paper published in Computers & Geosciences outlines a process that might help. "Our work establishes a new method to couple geographic ...

Astronomers put forward new theory on size of black holes

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: