Alignment of supermassive black holes

aligned BH

This is an image of the deep radio map covering the region with aligned galaxy jets. The image on the left has white circles around the aligned galaxies; the image on the right is without the circles.
Credit: Andrew Russ Taylor


Astronomers detected a group of supermassive black holes that are aligned, i.e. their axe of rotation points in the same direction. Observations were carried out using the Giant Metrewave Radio Telescope (GMRT) in India. In the past, studies have found evidence of orientations of quasar polarization position angles (e.g. Hutsemekers et al. 2014).

Since huge distances separate the aligned black holes, there is no way of exchanging information or influencing each other directly, as pointed out by Andrew Russ Taylor, lead author of the relevant study. Therefore, the only explanation for this alignment is that it occurred during the formation of the host galaxies in the early universe. 13.8 billion years ago, these galaxies occupied the same region of the primordial universe. As the universe expanded the galaxies were drifted apart to the position we currently observe them. The fact that the black holes retain their common properties throughout the cosmic time provides scientists an incredible opportunity to study how the small scale structure of the early universe influences the large scale structure today.


Publication: Taylor & Jagannathan 2016