Quasars large-scale structure

alignment of quasar across billions of light-years with large-scale structure

This very detailed simulation of large scale structure was created as part of the Illustris simulation. The distribution of dark matter is shown in blue and the gas distribution in orange. This simulation is for the current state of the Universe and is centered on a massive galaxy cluster. The region shown is about 300 million light-years across. (Credit Illustris Collaboration)

“A correlation between the orientation of quasars and the structure they belong to is an important prediction of numerical models of evolution of our Universe. Our data provide the first observational confirmation of this effect, on scales much larger that what had been observed to date for normal galaxies,” adds Dominique Sluse of the Argelander-Institut für Astronomie in Bonn, Germany and University of Liège.

The team could not see the rotation axes or the jets of the quasars directly. Instead they measured the polarization of the light from each quasar and, for 19 of them, found a significantly polarized signal. The direction of this polarization, combined with other information, could be used to deduce the angle of the accretion disc and hence the direction of the spin axis of the quasar.

“The alignments in the new data, on scales even bigger than current predictions from simulations, may be a hint that there is a missing ingredient in our current models of the cosmos,” concludes Sluse.