Galaxy 1,000 times brighter than Milky Way discovered

London

Scientists have discovered a very distant galaxy, some 10 thousand million light years away, which is about 1,000 times brighter than the Milky Way.

It is the brightest of the submillimetre galaxies, which have a very strong emission in the far infrared, researchers said.

Scientists led by Anastasio Diaz-Sanches from Polytechnic University of Cartagena (UPCT) in Spain used gravitational lensing that acts as a sort of magnifier, changing the size and intensity of the apparent image of the original object.

"Thanks to the gravitational lens produced by a cluster of galaxies between ourselves and the source, which acts as if it was a telescope, the galaxy appears 11 times bigger and brighter than it really is, and appears as several images on an arc centred on the densest part of the cluster, which is known as an Einstein Ring," said Diaz-Sanchez.

"The advantage of this kind of amplification is that it does not distort the spectral properties of the light, which can be studied for these very distant objects as if they were much nearer," Diaz-Sanchez said.

To find this galaxy, a search of the whole sky was carried out, combining the data bases of the satellites WISE and Planck in order to identify the brightest submillimetre galaxies.

The galaxy is notable for having a high rate of star formation. It is forming stars at a rate of 1,000 solar masses per year, compared to the Milky Way, which is forming stars at a rate of some twice a solar mass per year.

“This type of object harbours the most powerful star forming regions known in the universe. The next step will be to study their molecular content," said Susana Iglesias- Groth, an astrophysicist at Instituto de Astrofisica de Canarias (IAC) in Spain.

The fact that the galaxy is so bright, its light is gravitationally amplified, that allowed scientists to look into its internal properties, which would otherwise not be possible with such distant galaxies.

The research was published in the Astrophysical Journal Letters. PTI