XMM-Newton spots the greatest of great balls of fire

Jun 12, 2006
XMM-Newton spots the greatest of great balls of fire
This X-ray image shows a comet-like blob of gas about 5 million light-years long hurling through a distant galaxy cluster at nearly 1 000 kilometres per second. The 'comet' is confined to the orange regions in this image. The head is the lower right, with reddish areas. The tail fans outward because there is less pressure to confine it. The colour red refers to regions of lower entropy, a thermodynamical measure of disorder. The orange regions have higher entropy. This entropy map, different from brightness or temperature, helps scientists separate the cold and dense gas of the 'comet' from the hotter and more rarefied gas of the cluster. The data show with remarkable detail the process of gas being stripped from the comet's core (entropy goes up) and forming a large tail containing lumps of colder and denser gas. The 'comet' itself is a low-entropy gas; the ambient medium is a high entropy gas; the core of the comet has even lower entropy. The researchers estimate that a sun's worth of mass is lost every hour. Credit: University of Maryland, Baltimore County (UMBC)

Thanks to data from ESA's XMM-Newton X-ray satellite, a team of international scientists found a comet-like ball of gas over a thousand million times the mass of the sun hurling through a distant galaxy cluster over 750 kilometres per second.

This colossal 'ball of fire' is by far the largest object of this kind ever identified. The gas ball is about three million light years across, or about five thousand million times the size of our solar system. It appears from our perspective as a circular X-ray glow with a comet-like tail nearly half the size of the moon.

"The size and velocity of this gas ball is truly fantastic," said Dr Alexis Finoguenov, adjunct assistant professor of physics in the Department of Physics at the University of Maryland, Baltimore County (UMBC), and an associated scientist at the Max Planck Institute for Extra-Terrestrial Physics in Garching, Germany. "This is likely a massive building block being delivered to one of the largest assembly of galaxies we know."

The gas ball is in a galaxy cluster called Abell 3266, millions of light years from Earth, thus posing absolutely no danger to our solar system. Abell 3266 contains hundreds of galaxies and great amounts of hot gas that is nearly a hundred million degrees. Both the cluster gas and the giant gas ball are held together by the gravitational attraction of unseen dark matter.

"What interests astronomers is not just the size of the gas ball but the role it plays in the formation and evolution of structure in the universe," said Dr Francesco Miniati, who worked on this data at UMBC while visiting from the Swiss Federal Institute of Technology in Zurich, Switzerland.

Abell cluster 3266 is part of the Horologium-Reticulum super-cluster and is one of the most massive galaxy clusters in the southern sky. It is still actively growing in size, as indicated by the gas ball, and will become one of the largest mass concentrations in the nearby universe.

Using XMM-Newton data, the science team produced an entropy map (entropy is a thermodynamical property that provides a measure of disorder). The map allows for the separation of the cold and dense gas of the comet from the hotter and more rarefied gas of the cluster. This is based on X-ray spectra. The data show with remarkable detail the process of gas being stripped from the comet's core and forming a large tail containing lumps of colder and denser gas. The researchers estimate that a sun's worth of mass is lost every hour.

"In Abell 3266 we are seeing structure formation in action," said Prof. Mark Henriksen (UMBC), co-author of the results. "Dark matter is the gravitational glue holding the gas ball together. But as it races through the galaxy cluster, a tug-of-war ensues where the galaxy cluster eventually wins, stripping off and dispersing gas that perhaps one day will seed star and galaxy growth within the cluster."

Source: European Space Agency

Explore further: Comet Jacques makes a 'questionable' appearance

add to favorites email to friend print save as pdf

Related Stories

Hoverbike drone project for air transport takes off

6 hours ago

What happens when you cross a helicopter with a motorbike? The crew at Malloy Aeronautics has been focused on a viable answer and has launched a crowdfunding campaign to support its Hoverbike project, "The ...

Study indicates large raptors in Africa used for bushmeat

7 hours ago

Bushmeat, the use of native animal species for food or commercial food sale, has been heavily documented to be a significant factor in the decline of many species of primates and other mammals. However, a new study indicates ...

'Shocking' underground water loss in US drought

7 hours ago

A major drought across the western United States has sapped underground water resources, posing a greater threat to the water supply than previously understood, scientists said Thursday.

Recommended for you

Comet Jacques makes a 'questionable' appearance

20 hours ago

What an awesome photo! Italian amateur astronomer Rolando Ligustri nailed it earlier today using a remote telescope in New Mexico and wide-field 4-inch (106 mm) refractor. Currently the brightest comet in ...

Image: Our flocculent neighbour, the spiral galaxy M33

20 hours ago

The spiral galaxy M33, also known as the Triangulum Galaxy, is one of our closest cosmic neighbours, just three million light-years away. Home to some forty billion stars, it is the third largest in the ...

Image: Chandra's view of the Tycho Supernova remnant

Jul 25, 2014

More than four centuries after Danish astronomer Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is now a bright source of X-rays. The supersonic expansion of ...

User comments : 0