Washington, Nov 16 (IANS): A team of astronomers has solved the mystery as to why certain young galaxies flame out in a blaze of glory.

These young "starburst" galaxies that would shut down their star formation to join a category scientists call "red and dead" had puzzled astronomers for long.

Starburst galaxies result from the merger or close encounter of two separate galaxies.

"To form stars you need dense gas. When the gas gets dense enough and is not too hot, small portions of that gas can collapse to form stars. Without a lot of cool dense gas, stars cannot be formed," said Gregory Rudnick, associate professor of physics and astronomy at the University of Kansas in the US.

Previous research showed spouts of gas shooting outward from such galaxies at up to two million miles per hour.

But astronomers did not know of what led to the gas being expelled.

Rudnick and fellow researchers found that energy from the star formation itself created a shortage of gas within the starburst galaxies, shutting down the potential for further crafting of stars.

"There is so much star formation that it is possible the energy from the star formation itself is able to stop the star formation," Rudnick added.

Black holes once thought to be responsible for causing these outflows did not have any role to play in them, said the study that appeared in the journal Monthly Notices.