Gas Blob Resembles Gigantic Comet

News
By published
Gas Blob Resembles Gigantic Comet
X-ray image showing a comet-like blob of gas about 5 million light-years long hurling through a distant galaxy cluster over 500 miles 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 color red refers to regions of lower entropy. The orange regions have higher entropy. (Image credit: ESA/XMM-Newton/Finoguenov et al.)

A ball of gas more massive than a billion suns is hurtling like an enormous comet through the interior of a distant galaxy cluster.

The massive structure is held together by mysterious dark matter, astronomers said today, but it is steadily breaking apart and becoming fuel for new stars.

"This is likely a massive building block being delivered to one of the largest assembly of galaxies we know," said study team member Alexis Finoguenov of the University of Maryland, Baltimore County.

Nicknamed "comet," the gas ball is the largest of its kind ever detected. It measures about three million light-years across, or around five billion times the size of our solar system. The gas is estimated to be about 84 million degrees Fahrenheit (about 46 million degrees Celsius). Although this might seem hot to us, it is still relatively cool compared to some interstellar gas.

Using X-ray data from the European Space Agency's XMM-Newton satellite, the researchers produced an entropy map of Abell 3266 and the gas ball. In thermodynamics, entropy is a measure of the degree of randomness or disorder in a system.

The map shows gas being stripped from the gas comet's core and forming a large tail containing scattered clumps of cold, dense gas. The researchers estimate that about a sun's worth of mass is being lost by the gas comet every hour.

The gas comet is so massive that it could probably form it's own galaxy, but the researchers think the more likely scenario is that it'll add to the bulk of a giant elliptical galaxy already forming in the center of Abell 3266.

"It'll sort of collapse down to the center, and in a few billion years off it'll become stars in that galaxy," Henriksen told SPACE.com.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.

Ker Than
Staff Writer

Ker Than is a science writer and children's book author who joined Space.com as a Staff Writer from 2005 to 2007. Ker covered astronomy and human spaceflight while at Space.com, including space shuttle launches, and has authored three science books for kids about earthquakes, stars and black holes. Ker's work has also appeared in National Geographic, Nature News, New Scientist and Sky & Telescope, among others. He earned a bachelor's degree in biology from UC Irvine and a master's degree in science journalism from New York University. Ker is currently the Director of Science Communications at Stanford University.