Scientists Reveal Twin Quasar Brightness Mystery

Astronomers managed to establish just recently that the Q0957+561 quasar, also called the twin quasar, doesn't owe its intermittent brightness to possible attractions from celestial bodies around. Instead, the unusual glow comes from the region itself, located approximately 9 billion light-years away from Earth, in the Ursa Major constellation. Spanish researchers were able to solve this mystery just now, after 30 years in which the object has sparked numerous controversies as to what was causing its unusual behavior.
 

Quasars, standing for quasi-stellar radio sources, are in fact very strong and powerful active galactic nuclei that were primarily identified due to the fact that they give out high redshift sources of electromagnetic energy, including radio waves and visible light. Up until this point, there is no strong consensus in the academic community as to what the precise origin of these objects might be, but experts agree that quasars usually encompass the central supermassive black hole of a galaxy, and that they are powered by its accretion disc.
 

“Just as the force of the Earth's gravity determines the movement of a rocket or the moon, the concentration of a vast mass (such as a cluster of galaxies situated between Q0957+561 and the Earth) is capable of substantially deviating rays of light from the far away quasar and producing two images of it, A and B,” explains University of Cantabria Gravitational Lenses Group specialist, Luis J. Goicoechea.
 

The researcher, who published the latest find in a recent edition of the journal Astronomy & Astrophysics, likens this effect to mirages that occur in deserts. Basically, the major controversy between astronomers concerned the origin of the light pulsation. While some said that it belonged to the body itself (which now turned to be correct), others claimed that gravitational influences from nearby galaxies or black holes were responsible for the fluctuations.

“It seems the attractive hypothesis of a large population of dark objects with planetary mass in the galaxy’s halo has disappeared, since the variability found in our experiment is of intrinsic origin to the quasar,” the researcher says. Apparently, one light pulse in the A image was reflected in image B 14 months later, very accurately. This wouldn't have happened if gravitational forces were to act on the process.