Solving the Quasar Enigma

Scientists have unlocked one of the mysteries of quasars by discovering that they are ignited by galaxies colliding

Discovered six decades ago, quasars have long puzzled scientists regarding their origin. They are as luminous as a trillion stars confined to the volume of our Solar System. Recent research, led by scholars from the Universities of Sheffield and Hertfordshire has shed light on this enigma, revealing that the vigorous activity of quasars emerges from the collision of galaxies.

The collisions came to light as researchers examined galaxies housing quasars through profound imaging using the Isaac Newton Telescope in La Palma. In these galaxies, distorted formations were observed in their outer reaches. Typically, galaxies harbor massive black holes at their cores, surrounded by substantial gas reserves. However, this gas often orbits far from the black holes in what we call an accretion disk. Galaxy collisions compel this gas towards the central black hole. Just before consumption, the gas emits an immense amount of energy as radiation, generating the distinctive brilliance of quasars.

The birth of a quasar can hold profound implications for its host galaxy, expelling most of its gas and thwarting star formation for billions of years. For the first time, a collection of quasars of this magnitude has been scrutinized with such precision. By comparing observations of 48 quasars and their galaxies to images of over 100 non-quasar galaxies, researchers deduced that quasar-hosting galaxies are about three times more likely to be engaged in interactions or collisions with other galaxies.

The study published this week in Monthly Notices of the Royal Astronomical Society has provided a significant step forward in our understanding of how these powerful objects are triggered and fueled. This study marks a significant stride in advancing our comprehension of the triggers and sustenance of these formidable celestial entities.

Sources: Sciencedaily, ING Research