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‘Wasteful’ galaxies launch heavy elements into deep space

‘Wasteful’ galaxies launch heavy elements into deep space
The spiral galaxy NGC 4258, also known as M106, has two extra spiral arms as seen in this undated composite image X-ray data from NASA?s Chandra X-ray Observatory, radio data from the NSF?s Karl Jansky Very Large Array, optical data from NASA?s Hubble Space Telescope and infrared data from NASA?s Spitzer Space Telescope. The image was published in the June 20, 2014 issue of The Astrophysical Journal Letter. REUTERS/NASA/Handout via Reuters (UNITED STATES - Tags: SCIENCE TECHNOLOGY) ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS

New York: Galaxies “waste” large quantities of heavy elements generated by star formation by ejecting them up to a million light years away into their surrounding halos and deep space, says a study.

More oxygen, carbon and iron atoms exist in the sprawling, gaseous halos outside of galaxies than exist within the galaxies themselves, leaving the galaxies deprived of raw materials needed to build stars and planets, the findings showed.

“Previously, we thought that these heavier elements would be recycled into future generations of stars and contribute to building planetary systems,” said lead author of the study Benjamin Oppenheimer from University of Colorado Boulder (CU-Boulder) in the US.

“As it turns out, galaxies are not very good at recycling,” Oppenheimer pointed out.

The near-invisible reservoir of gas that surrounds a galaxy, known as the circumgalactic medium (CGM), is thought to play a central role in cycling elements in and out of the galaxy, but the exact mechanisms of this relationship remain elusive.

A typical galaxy ranges in size from 30,000 to 100,000 light years while the CGM can span up to a million light years.

The researchers used data from the Cosmic Origin Spectrograph (COS), a $70 million instrument designed at CU-Boulder and built by Colorado-based Ball Aerospace Technology Corp, to study the composition of the CGM.

The instrument is installed on NASA’s Hubble Space Telescope and uses ultraviolet spectroscopy to study the evolution of the universe.

After running a series of simulations, the researchers found that the CGMs in both spiral and elliptical galaxies contained more than half of a galaxy’s heavier elements, suggesting that galaxies are not as efficient at retaining their raw materials as previously thought.