Quasars Align across the Cosmos

The Universe Throws Yet Another Solveable Mystery at Us

So many cool science stories, so little time! Against the backdrop of the ongoing saga of Rosetta at Comet 67P (and cool results are starting to flow from the Philae lander, which I’ll talk about in another entry), the rest of the universe has been ticking merrily away, providing a constant stream of fascinating information.

For example, here’s a story to get your thinking, It involves the large-scale structure of the universe and a curious property of quasars. You know what a quasar is, right? It’s an active supermassive black hole at the center of a galaxy. There are countless numbers of these eerily bright objects scattered throughout the universe. These incredibly massive black holes are usually surrounded by dense, hot disks funneling material into the black hole. This action produces tremendous jets of superheated material threaded with strong magnetic fields. These jets extend out across many light-years of space.

These objects, called quasars (short for quasi-stellar radio sources) are incredibly bright in radio frequencies, as well as visible light. Astronomers studying quasars measure various characteristics in order to understand what they’re doing and what effects they have on their galaxies. One such characteristic is the spin of a quasar — its spin rate and its spin axis.

A research team using the European Southern Observatory’s Very Large telescope has been studying light polarized light streaming from 93 of these quasars spread out across billions of light-years, as they appeared when the universe was about one-third of its current age. (Polarized light can give hints about the accretion disk and its spin direction.) To their surprise, the observers have found that the rotation axes of those quasars are parallel to each other.

This video shows that if you back off a little and look at the distribution of galaxies across billions and billions of light-years, you see them fall into a graceful cosmic web of filaments and clumps outlining huge voids where there are few galaxies. This is called the “large-scale structure of the universe”. When the astronomers superimposed the quasars in their study over a map of the large-scale structure, they found that nearly all of the rotation axes of the quasars pointed along the filaments they existed in at that time. (If you want to know the details of how the astronomers found this amazing alignment, check out this press release from ESO.)

This arrangement is not just by chance. There’s a physical reason WHY this is happening — perhaps due to the influence of nearby dark matter? It’s not clear yet why these early quasars are spinning away in parallel across vast distances in the early cosmos. This finding will certainly be added to cosmologist’s working models of the early universe!