X-shaped galaxies have long puzzled scientists who have wondered what the cause of their formation may be. Now, new observations of the South African MeerKAT telescope of one such galaxy called PKS 2014-55 may have finally provided an answer.
"Several possible explanations have been proposed to understand this phenomenon. These include changes in the direction of spin of the black hole at the center of the galaxy, and associated jets, over millions of years; two black holes each associated with a pair of jets; and material falling back into the galaxy being deflected into different directions forming the other two arms of the ‘X’," said South African Radio Astronomy Observatory (SARAO)'s media release.
Which of these three was most probable according to the recent observations? The last one as the observations showed material “turning the corner” as it flows back towards the host galaxy.
"MeerKAT was designed to be the best of its kind in the world. It’s wonderful to see how its unique capabilities are contributing to resolving longstanding questions related to the evolution of galaxies," said Bernie Fanaroff, former director of the SKA South Africa project that built MeerKAT, and a co-author of the new study.
These revelations were made by a team from SARAO, the (US) National Radio Astronomy Observatory (NRAO), the University of Pretoria, and Rhodes University thanks to the high-quality imaging provided by the recently completed MeerKAT telescope.
MeerKAT consists of 64 radio dishes located in the Karoo semi-desert in the Northern Cape province of South Africa. “MeerKAT is one of a new generation of instruments whose power solves old puzzles even as it finds new ones – this galaxy shows features never seen before in this detail which are not fully understood," said study lead author William Cotton of the NRAO.