Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


XMM-Newton pinpoints intergalactic polluters

Warm gas escaping from the clutches of enormous black holes could be the key to a form of intergalactic ‘pollution’ that made life possible, according to new results from ESA’s XMM-Newton space observatory, published today.

Black holes are not quite the all-consuming monsters depicted in popular culture.

Until gas crosses the boundary of the black hole known as the event horizon, it can escape if heated sufficiently. For decades now, astronomers have watched warm gas from the mightiest black holes flowing away at speeds of 1000-2000 km/s and wondered just how much gas escapes this way. XMM-Newton has now made the most accurate measurements yet of the process.

The international team of astronomers, led by Yair Krongold, Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, targeted a black hole two million times more massive than the Sun at the centre of the active galaxy NGC 4051.

Previous observations had only revealed the average properties of the escaping gas. XMM-Newton has the special ability to watch a single celestial object with several instruments at the same time. With this, the team collected more detailed information about variations in the gas’ brightness and ionization state.

The team also saw that the gas was escaping from much closer to the black hole than previously thought. They could determine the fraction of gas that was escaping. “We calculate that between 2–5 percent of the accreting material is flowing back out,” says team member Fabrizio Nicastro, Harvard-Smithsonian Centre for Astrophysics. This was less than some astronomers had expected.

The same heating process that allows the gas to escape also rips electrons from their atomic nuclei, leaving them ionised. The extent to which this has happened in an atom is known as its ionisation state. In particular, metals always have positive ionisation states.

The warm gas contains chemical elements heavier than hydrogen and helium. Astronomers term them ‘metals’ since they are elements in which electrons are ripped away and they have positive ionisation states - like metals. They include carbon, the essential element for life on Earth. These metals can only be made inside stars, yet they pollute vast tracts of space between galaxies. Astronomers have long wondered how they arrived in intergalactic space.

This new study provides a clue. More powerful active galaxies than NGC 4051, known as quasars, populate space. They are galaxies in which the central black hole is feeding voraciously. This would mean that quasars must have escaping gas that could carry metals all the way into intergalactic space.

If quasars are responsible for spraying metals into intergalactic space, the pollution would more likely be found in bubbles surrounding each quasar. So, different parts of the Universe would be enriched with metals at different speeds. This may explain why astronomers see differing quantities of metals depending upon the direction in which they look.

However, if the fraction of escaping gas is really as low as XMM-Newton shows in NGC 4051, astronomers need to find another source of intergalactic metals. This might be the more prevalent star-forming galaxies called Ultra Luminous Infra Red Galaxies.

“Based on this one measurement, quasars can contribute some but not all of the metals to the intergalactic medium,” says Krongold.

To continue the investigation, the astronomers will have to use the same XMM-Newton technique on a more powerful active galaxy. Such observations will allow them to determine whether the fraction of gas escaping changes or stays the same. If the fraction goes up, they will have solved the puzzle. If it stays the same, the search will have to continue.

Norbert Schartel | alfa
Further information:

More articles from Physics and Astronomy:

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Innovative technique for shaping light could solve bandwidth crunch
20.10.2016 | The Optical Society

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>