Black Holes Stop Star Births In Galaxies
May 9, 2012

Black Holes Stop Star Births In Galaxies

Astronomers have found that a number of stars that form during the early lives of galaxies may be influenced by the massive black holes in the center of the celestial suburb.

The team, using the European Space Agency's (ESA) Herschel Space Observatory, looked a distant galaxies that were far enough away that the light reaching Herschel is from billions of years ago.

"Herschel provides a new perspective and is conducting a number of surveys of galaxies near and far, in order to unravel the mysteries of the formation and evolution of galaxies across cosmic time," Göran Pilb'ratt, the ESA Herschel Project Scientist, said in a recent press release.

The study used images from the SPIRE camera on board Herschel to calculate the amount of star formation in distance galaxies.

The results show that the fastest-growing black holes are in galaxies with very little star formation.  Once the radiation coming from close to the black hole exceeds a certain power, it switches off star formation in the galaxy.

"This fantastic result provides an amazing link between black holes and star formation in the early Universe," Seb Oliver from the University of Sussex and co-leader of the HerMES project said.

The most likely explanation to the discovery is that the winds coming from around these black holes are preventing the gas and dust in the rest of the galaxy from forming stars.

"It is a huge clue to this decade old riddle and could mean that once a black hole is big enough and producing enough radiation, it somehow shuts down the formation of stars in the surrounding galaxy," Oliver said.

The researchers compared their infrared readings with X-rays streaming from the active central black holes in the survey's galaxies, which was measured by NASA's Chandra X-ray Observatory.

"Now that we see the relationship between active supermassive black holes and star formation, we want to know more about how this process works," Bill Danchi, Herschel program scientist at NASA Headquarters in Washington, said in a press release.

"Does star formation get disrupted from the beginning with the formation of the brightest galaxies of this type, or do all active black holes eventually shut off star formation, and energetic ones do this more quickly than less active ones?"

Professor Matt Griffin of Cardiff University, who is the Principal Investigator of the international team which built the Herschel-SPIRE instrument, said the discovery is important because it shows the sensitivity of SPIRE allows astronomers to look back in time and understand the early history of the universe.

"Only a small fraction of the instrument's observations have been fully analyzed so far, and we're looking forward to many more exciting results," Griffin said in the press release.

The research was published in the scientific journal Nature.