Thaindian News

Washington, June 25 (ANI): New data obtained from NASA’s Chandra X-ray Observatory and other telescopes has pinpointed the source of “cosmic blobs” as growing supermassive black holes.

This discovery helps resolve the true nature of gigantic blobs of gas observed around very young galaxies.

About a decade ago, astronomers discovered immense reservoirs of hydrogen gas, which they named “blobs”, while conducting surveys of young distant galaxies.

The blobs are glowing brightly in optical light, but the source of immense energy required to power this glow and the nature of these objects were unclear.

A long observation from Chandra has identified the source of this energy for the first time.

The X-ray data show that a significant source of power within these colossal structures is from growing supermassive black holes partially obscured by dense layers of dust and gas.

The fireworks of star formation in galaxies are also seen to play an important role, thanks to Spitzer Space Telescope and ground-based observations.

“For ten years, the secrets of the blobs had been buried from view, but now we’ve uncovered their power source,” said James Geach of Durham University in the United Kingdom, who led the study.

“Now, we can settle some important arguments about what role they played in the original construction of galaxies and black holes,” he added.

Galaxies are believed to form when gas flows inwards under the pull of gravity and cools by emitting radiation.

This process should stop when the gas is heated by radiation and outflows from galaxies and their black holes.

Blobs could be a sign of this first stage, or of the second.

Based on the new data and theoretical arguments, Geach and his colleagues show that heating of gas by growing supermassive black holes and bursts of star formation, rather than cooling of gas, most likely powers the blobs.

The implication is that blobs represent a stage when the galaxies and black holes are just starting to switch off their rapid growth because of these heating processes.

This is a crucial stage of the evolution of galaxies and black holes - known as “feedback” - and one that astronomers have long been trying to understand.

“We’re seeing signs that the galaxies and black holes inside these blobs are coming of age and are now pushing back on the infalling gas to prevent further growth,” said coauthor Bret Lehmer, also of Durham.

“Massive galaxies must go through a stage like this or they would form too many stars and so end up ridiculously large by the present day,” he added. (ANI)