Paris, Oct 5 : The European Space Agency’s (ESA’s) orbiting gamma-ray observatory, Integral has helped astronomers discover a gamma ray lighthouse shining at the edge of our universe.

Scientists discovered the object, known by its catalogue name IGR J22517+2218, this year. However, its nature is unknown, they say.

Scientists say this is not an unusual situation, as around 30 percent of the sources discovered by Integral remain unidentified so far.

“All astronomers know for certain, is that there are celestial sources out there, pumping gamma rays into space. However, the identification of the sources with individual celestial objects will have to wait for more detailed observations in other wavelengths,” said Loredana Bassani from IASF-Bologna/INAF, Italy, who together with colleagues investigated this distant galaxy.

“In fact, this was the case for IGR J22517+2218. It came as a surprise when NASA's Swift satellite recorded the object in X-rays, giving its position within much more precision than can be achieved in gamma rays. IGR J22517+2218 was identified with the already known active galaxy MG3 J225155+2217. This galaxy is so distant that it is the furthest celestial object ever to be recorded by Integral,” Bassani said.

Bassani said all active galaxies were powered by supermassive black holes, supermassive objects that contained between a million and several thousand million times the mass of the Sun.

“They generate a gravitational field so large that they swallow any matter passing nearby, releasing enormous amounts of energy in the process. In the case of IGR J22517+2218, the Integral observations show that it is a gargantuan powerhouse, throwing out stupendous quantities of gamma rays. It is gobbling up an entire solar system every few days and hurling the energy out in gamma-rays,” Bassani said.

Bassani said the Integral observations further showed that the galaxy was one of a special kind of active galaxy, known as a blazar.

Blazars are the most energetic of the active galaxies. They tend to have two major peaks of emission.

In objects similar to IGR J22517+2218, one peak occurs in infrared wavelengths and is produced by the radiation given off by electrons spiralling around the magnetic field lines. The other peak occurs at high-energy gamma-ray wavelengths and is produced by those same electrons colliding with photons of light.

However, the Integral data showed some curiosities, Bassani said.

In the case of IGR J22517+2218, the object appeared to have only one peak, which occurred in neither of the conventional wavelength ranges but, rather, in the low-energy gamma ray band.

Bassani said, either the infrared peak had moved up in energy, or the high-energy gamma-ray peak moved down.

“This is a very peculiar object. We have been able to classify it as a blazar but it has some strange characteristics. Either way, when the team can work out what this means, it will doubtlessly tell them a lot about active galaxies, and blazars in particular,” said Bassani.

“Whatever we discover, this object will stretch our understanding of the blazars,” Bassani added.

The team now plans to continue observing this object at all wavelengths in an effort to build up a full picture of the radiation given out by this celestial object.

In this way, it will be possible to piece together the manner in which the supermassive black hole at the heart of IGR J22517+2218 is devouring its surroundings, Bassani said. (ANI)