Process of ‘cosmic chaos’ involved in the birth of stars, says NASA

28 Oct 2014

A supermassive black hole captured by the Candra X-ray Observatory. Image via NASA/CXC/CfA/R.Kraft et al

For decades, the explanation as to how stars are born has eluded scientists but now a study looking at galaxy clusters could find an answer in something they have described as ‘cosmic chaos’.

From US space agency NASA’s analysis of the Perseus and Virgo galaxy clusters captured by its Chandra X-ray Observatory space telescope, these clusters are the largest objects in the universe, containing hundreds, or indeed, thousands of different galaxies that are immersed in blistering hot gas and whose temperatures measure somewhere in the region of millions of degrees centigrade.

From scientists’ current understanding and observations, this ultra-hot gas in clusters should cool down sufficiently to allow stars to develop, but for the Perseus and Virgo clusters, the temperature remains relatively constant, which confused the team and its lead researcher, Irina Zhuravleva.

While the scientists were aware that supermassive black holes, centred in large galaxies in the middle of galaxy clusters, pump vast quantities of energy around them in powerful jets of energetic particles creating cavities in the hot gas, the process of how this transferred to colder areas was unknown.

Chandra X-ray Observatory images of the Perseus and Virgo galaxy clusters. Image via NASA/CXC/Stanford/I. Zhuravleva et al

Now however, the team has theorised that the interaction of these cavities with the hot gas may be generating turbulence, or ‘cosmic chaos’, which then disperses to keep the gas hot for billions of years.

If this process is correct, then this would confirm that the process of star birth is reliant on the cooling of these enormous celestial entities.

Discussing the findings, Zhuravleva said, “We knew that somehow the gas in clusters is being heated to prevent it cooling and forming stars. The question was exactly how. We think we may have found evidence that the heat is channelled from turbulent motions, which we identify from signatures recorded in X-ray images.”

Colm Gorey was a senior journalist with Silicon Republic