ICRAR: Hungry black hole consumes material faster than thought possible

A rendering of what Black Hole P13 would look like close up. 

Credit: by Tom Russell (ICRAR) using software created by Rob Hynes (Louisiana State University).

Astronomers have discovered a black hole that is consuming gas from a nearby star 10 times faster than previously thought possible.

The black hole, known as P13, lies on the outskirts of the galaxy NGC7793 about 12 million light years from Earth and is ingesting a weight equivalent to 100 billion billion hot dogs every minute.

The discovery was published today in the journal Nature.

International Centre for Radio Astronomy Research (ICRAR) astronomer Dr Roberto Soria, who is based at ICRAR's Curtin University node, said that as gas falls towards a black hole it gets very hot and bright.

He said scientists first noticed P13 because it was a lot more luminous than other black holes, but it was initially assumed that it was simply bigger.

"It was generally believed the maximum speed at which a black hole could swallow gas and produce light was tightly determined by its size," Dr Soria said.

"So it made sense to assume that P13 was bigger than the ordinary, less bright black holes we see in our own galaxy, the Milky Way."

When Dr Soria and his colleagues from the University of Strasbourg measured the mass of P13 they found it was actually on the small side, despite being at least a million times brighter than the Sun.

It was only then that they realised just how much material it was consuming.

"There's not really a strict limit like we thought, black holes can actually consume more gas and produce more light," Dr Soria said.

Dr Soria said P13 rotates around a supergiant 'donor' star 20 times heavier than our own Sun.

He said the scientists saw that one side of the donor star was always brighter than the other because it was illuminated by X-rays coming from near the black hole, so the star appeared brighter or fainter as it went around P13.

Primary Image: This is a combined optical /X-ray image of NGC 7793. 

Inset image: This is a rendering of what P13 would look like close up. 

Credit: X-ray (NASA /CXC /Univ of Strasbourg /M. Pakull et al); Optical (ESO /VLT /Univ of Strasbourg /M. Pakull et al); H-alpha (NOAO /AURA /NSF /CTIO 1.5m). 

Insert Image: created by Tom Russell (ICRAR) using software created by Rob Hynes (Louisiana State University).

"This allowed us to measure the time it takes for the black hole and the donor star to rotate around each other, which is 64 days, and to model the velocity of the two objects and the shape of the orbit," Dr Soria said.

"From this, we worked out that the black hole must be less than 15 times the mass of our Sun."

Dr Soria said P13 is a member of a select group of black holes known as ultraluminous X-ray sources.

"These are the champions of competitive gas eating in the Universe, capable of swallowing their donor star in less than a million years, which is a very short time on cosmic scales," he said.

More information: 'A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source' was published in Nature, 9 October 2014. C. Motch, M. W. Pakull, R. Soria, F. Grise, G. Pietrzynski. DOI: 10.1038/nature13730

ESA SARAS: Catching signals faster - Video

SARAS – a Spanish acronym for ‘Fast Acquisition of Satellites and Launchers’ – enables ground stations to acquire signals from new satellites faster and more accurately than ever before. 

A circular array of eight small radio-frequency sensors are mounted around the rim of an existing dish antenna. 

It was fitted to the 15 m-diameter dish at ESA’s ESAC Establishment in Spain, seen here during upgrade work, in 2013.

Since then, it has been extensively tested, receiving signals from missions including CryoSat, XMM, and Swarm. 

It also helps the station to acquire signals from multisatellite missions, such as the three-craft Swarm.

Ultrafast heating of water: This pot boils faster than you can watch

A single terahertz flash can heat the water cloud to 600 degrees centigrade, while leaving all water molecules intact. 

Credit: Oriol Vendrell/DESY

Scientists from the Hamburg Center for Free-Electron Laser Science (CFEL) have devised a novel way to boil water in less than a trillionth of a second.

The theoretical concept, which has not yet been demonstrated in practice, could heat a small amount of water by as much as 600 degrees Celsius in just half a picosecond (a trillionth of a second).

That is much less than the proverbial blink of an eye: one picosecond is to a second what one second is to almost 32 millennia. This would make the technique the fastest water-heating method on Earth.

The novel concept opens up interesting new ways for experiments with heated samples of chemical or biological relevance, as the inventors report in this week's issue of the scientific journal Angewandte Chemie International Edition (Nr. 51, 16 December).

"Water is the single most important medium in which chemical and biological processes take place," explains Deutsches Elektronen-Synchrotron (DESY) scientist Dr. Oriol Vendrell from the Center for Free-Electron Laser Science CFEL, a cooperation of Deutsches Elektronen-Synchrotron (DESY), the University of Hamburg and the German Max Planck Society.

"Water is not just a passive solvent, but plays an important role in the dynamics of biological and chemical processes by stabilising certain chemical compounds and enabling specific reactions."

All it takes for superfast water heating is a concentrated flash of terahertz radiation. Terahertz radiation consists of electromagnetic waves with a frequency between radio waves and infrared.

Terahertz flashes can be generated with devices called free-electron lasers that send accelerated electrons on a well defined slalom course.

The particles emit electromagnetic waves in each bend that add up to an intense laser like pulse. The terahertz pulse changes the strength of the interaction between water molecules in a very short time, which immediately start to vibrate violently.

The scientists calculated the interaction of the terahertz flash with bulk water. The simulations were performed at the Supercomputer Center Jülich and used a total of 200,000 hours of processor time by massively parallel computing.

On a single processor machine this would correspond to about 20 years of computation. "We have calculated that it should be possible to heat up the liquid to about 600 degrees Celsius within just half a picosecond, obtaining a transiently hot and structureless environment still at the density of the liquid, leaving all water molecules intact," explains Vendrell.

The novel method can only heat about one nanolitre (billionth of a litre) in one go. This may sound small, but is large enough for most experiments.

For comparison, ink-jet printers fire droplets that are as small as one picolitre, which is a thousand times less than a nanolitre.

More information: "Ultrafast Energy Transfer to Liquid Water by Sub-Picosecond High- Intensity Terahertz Pulses: An Ab Initio Molecular Dynamics Study"; Pankaj Kr. Mishra, Oriol Vendrell and Robin Santra; Angewandte Chemie International Edition, Vol. 52, Nr. 51, p. 13685-13687, 16. Dezember 2013; DOI: 10.1002/anie.201305991

Antarctic: Ice Sheet warming Faster

The West Antarctic Ice Sheet, whose melt may be responsible for 10 percent of the sea-level rise caused by climate change, is warming twice as quickly as previously thought, a recent study shows.

A re-analysis of temperature records from 1958 to 2010 revealed an increase of 2.4 degrees Celsius (36.3 degrees Fahrenheit) over the period -- three times the average global rise.

The increase was nearly double what previous research had suggested, and meant this was one of the fastest-warming regions on Earth, according to paper co-author David Bromwich of the Byrd Polar Research Center.

"Our record suggests that continued summer warming in West Antarctica could upset the surface balance of the ice sheet, so that the region could make an even bigger contribution to sea-level rise than it already does," he said.

Scientists believe the shrinking of the West Antarctic Ice Sheet is responsible for about 10 percent of global warming-related sea-level rise, which if unchecked threatens to flood many coastal cities within a few generations.

The sheet, a huge mass of ice up to four kilometres (2.5 miles) thick that covers the land surface and stretches into the sea, is melting faster than any other part of Antarctica.

Second Experiment Confirms Faster-Than-Light Neutrinos - Einstein's Theory questioned

A new experiment appears to provide further evidence that neutrinos can travel faster than light, contradicting Einstein's theory of relativity that underpins modern thinking of how the universe works.

Albert Einstein published his theory of relativity in 1905 and asserted that nothing - no matter how small - can travel faster than the speed of light, which is approximately 186,000 miles per second.

The experiment, which is the second of its kind this year, took place at the Gran Sasso laboratory in Italy and used a neutrino beam from CERN in Switzerland 450 miles away.

Scientists at the Italian Institute for Nuclear Physics (INFN) said in a statement that their new tests aimed to exclude one potential systematic effect that might have affected the original measurement.

"A measurement so delicate and carrying a profound implication on physics requires an extraordinary level of scrutiny," said Fernando Ferroni, president of the INFN.

Scientists were shocked in September when a similar experiment found that neutrinos had travelled faster than light and - in theory - arrived at their destination before they set off.

Reuters reports that physicists involved said they had checked and rechecked anything that could have produced a misreading before announcing what they had found.

In an attempt to rule out any margin for error, the beams sent by CERN in this latest experiment were a few nanoseconds shorter than those sent in the September experiment, with larger gaps of 524 nanoseconds between them, resulting in more accurate timing.

"In this way, compared to the previous measurement, the neutrinos bunches are narrower and more spaced from each other," the scientists said. "This permits to make a more accurate measure of their velocity at the price of a much lower beam intensity."

Although errors can still not be completely ruled out, this evidence does further suggest that Einstein's theory of relativity was incorrect, forcing a major rethinking about how the cosmos works. It may even mean that sending information back in time could be made possible.

Minotaur 4 Launches FASTRAC, STPSat-2, FASTSAT and FalconSat-5

Four satellites sit atop the Minotaur 4 rocket that launched them into space Nov. 19.

Clockwise from bottom are FASTRAC, STPSat-2, FASTSAT and FalconSat-5. Credit: NASA/Lou Hernandez/Air Force Space & Missile Systems Center

Built by the Virginia-based company Orbital Sciences, Corp., the Minotaur 4 rocket is expected to deliver all seven satellites, which carry a total of 16 separate experiments among them, to an orbit about 404 miles (650 kilometers) above Earth. The $170 million mission, STP-S26, is part of the Air Force's Space Test Program.
The payload on board:
FASTSATThis NASA craft — short for Fast, Affordable Science and Technology Satellite — weighs about 325 pounds (148 kilograms) and is about the size of a washing machine. It's part of a broader NASA effort to find ways to perform research in space cheaply and reliably.
The agency spent less than $12 million developing the spacecraft, agency officials have said.
FASTSAT is carrying six different scientific experiments. One of those is a smaller satellite called NanoSail-D, an 8.5-pound (3.9-kg) probe designed to eject from FASTSAT and deploy a solar sail in orbit. Solar sails catch photons from the sun much as ships' sails catch the wind.
NanoSail-D will use its solar sail to deorbit itself, potentially demonstrating a new way to bring satellites and debris back to Earth without any chemical propellant, NASA officials have said.
Also onboard FASTSAT are three NASA instruments designed to monitor space weather, as well as two payloads managed by the U.S. Air Force. One is a low-cost star-tracking instrument, and the other is a device that will evaluate techniques used to measure how beams of light move through Earth's atmosphere.
O/OREOS
NASA's O/OREOS (Organism/Organic Exposure to Orbital Stresses) is another demonstration satellite that was developed on the cheap (less than $1.75 million, officials have said).
O/OREOS is about the size of a loaf of bread and weighs 12 pounds (5.5 kg). It contains two experiments that will activate once the nanosatellite reaches low-Earth orbit.
One of these will characterize how microbes grow and reproduce in space, as well as how they adapt to the stresses of the space environment. The other will look at how space conditions affect four different classes of organic molecules, which are the building blocks of life.
STPSat-2
This U.S. Air Force microsatellite is the Minotaur 4's primary payload. STPSat-2 carries two payloads of its own: the Ocean Data Telemetry Microsat Link, which will relay data from ocean and terrestrial sensors, and the Space Phenomenology Experiment, which will evaluate sensor compatibility in space.

STPSat-2 will be the first satellite operated by a new command and control system called the Multi-Mission Space Operations Center. This ground system is designed to fly multiple constellations of spacecraft with various missions.

FASTRAC, FalconSat-5 and RAX.Also aboard the Minotaur are three other satellites called FASTRAC, FalconSat-5 and RAX.
FASTRAC — short for Formation Autonomy Spacecraft with Thrust, Relnav, Attitude and Crosslink —was developed by grad students and undergrads at the University of Texas, Austin.
FASTRAC consists of two satellites, each about the size of two car tires, that will separate from each other in orbit to demonstrate communication and coordination capabilities.
FalconSat-5 was also built by students — cadets at the U.S. Air Force Academy in Colorado Springs, Colo. The $11 million microsatellite carries several different payloads, which will monitor space weather and its effects on radio signals.
The Radio Aurora Explorer, or RAX, is a 6-pound (2.8-kg) nanosatellite. It's a joint effort of the University of Michigan and SRI International, and it's sponsored by the U.S. National Science Foundation.
RAX's primary mission is to study dense plasma clouds in Earth's upper atmosphere. These clouds can disrupt communication between Earth and orbiting spacecraft, and RAX's operators hope the little satellite's measurements can help minimize communication problems in the future.
All of these satellites — from FASTSAT to RAX — are launching as part of the U.S. Department of Defense's Space Test Program, which is managed by the Air Force.

Nanowires research: Walls Falling Faster For Solid-State Memory

After running a series of complex computer simulations, researchers have found that flaws in the structure of magnetic nanoscale wires play an important role in determining the operating speed of novel devices using such nanowires to store and process information.

The finding, made by researchers from the National Institute of Standards and Technology(NIST), the University of Maryland, and the University of Paris XI, will help to deepen the physical understanding and guide the interpretation of future experiments of these next-generation devices.

Magnetic nanowires store information in discrete bands of magnetic spins. One can imagine the nanowire like a straw sucking up and holding the liquid of a meticulously layered chocolate and vanilla milkshake, with the chocolate segments representing 1s and the vanilla 0s.

The boundaries between these layers are called domain walls. Researchers manipulate the information stored on the nanowire using an electrical current to push the domain walls, and the information they enclose, through the wire and past immobile read and write heads.

Interpretations of experiments seeking to measure how domain walls move have largely ignored the effects of "disorder"-usually the result of defects or impurities in the structure of the nanowires. To see how disorder affects the motion of these microscopic magnetic domains, NIST researchers and their colleagues introduced disorder into their computer simulations.

Their simulations showed that disorder, which causes friction within the nanowires, can increase the rate at which a current can move domain walls.

According to NIST physicist Mark Stiles, friction can cause the domain walls to move faster because they need to lose energy in order to move down the wire.

For example, when a gyroscope spins, it resists the force of gravity. If a little friction is introduced into the gyroscope's bearing, the gyroscope will fall over more quickly. Similarly, in the absence of damping, a domain wall will only move from one side of the nanowire to the other.

Disorder within the nanowire enables the domain walls to lose energy, which gives them the freedom to "fall" down the length of the wire as they move back and forth.