ALMA Captures Image of Gravitationally Lensed Galaxy SDP.81

SDP.81, a galaxy located nearly 12 billion light years from earth, is known as a starburst galaxy. It is known as so because of its unusual high rate of stellar birth producing a lot of light.

The earth-based Atacama Large Millimeter/submillimeter Array has found this galaxy to be extra special. The telescope has captured image of the galaxy and is considered to be the most high-resolution image of the galaxy ever produced.

It is because between the galaxy and earth, there is one more galaxy, which is massive enough the bend the light coming from SDP.81. It is magnifying and distorting and line it up in such a matter that the light from the galaxy appears to be in almost perfect circle, which is an effect known as Einstein ring.

Both factors - the gravitational lensing magnification and ALMA's strength allowed scientists to see the galaxy with so much precision. The researchers said that the galaxy is an ancient one and dates back almost to the beginning of the universe. It is estimated to be around 13.82 billion years ago.

"Gravitational lensing is used in astronomy to study the very distant, very early Universe because it gives even our best telescopes an impressive boost in power", said ALMA Deputy Program Scientist Catherine Vlahakis. With the help of exceptional detail in the new images provided by the ALMA, scientists will be able to gather all the information present in the distorted image seen in a ring and come up with a reconstruction of the true image of the distant galaxy.

The image was taken in October 2013 as a part of an ALMA program with an aim to test and verify the telescope's highest resolving power.