Scientists have made a groundbreaking discovery regarding quasars, which are the brightest and most powerful objects in the universe. The mystery behind what triggers their intense activity has puzzled researchers since their discovery 60 years ago. However, a new study led by scientists at the Universities of Sheffield and Hertfordshire has uncovered that the ignition of quasars is a consequence of galaxies colliding.
Using deep imaging observations from the Isaac Newton Telescope in La Palma, the scientists observed distorted structures in the outer regions of galaxies that house quasars, revealing the collisions. Most galaxies possess supermassive black holes at their centers and a significant amount of gas. However, the gas is typically out of reach of the black holes, orbiting at large distances from the galaxy centers. Collisions between galaxies force the gas towards the black hole, and just before it is consumed, it emits an immense amount of energy in the form of radiation, resulting in the characteristic brightness of a quasar. The findings were published in Monthly Notices of the Royal Astronomical Society.
Scientists have finally solved one of the biggest mysteries of quasars, which are the brightest and most powerful objects in the universe. The new discovery reveals that galaxies colliding is the trigger that ignites quasars. Quasars were first discovered 60 years ago, and in the decades since, the cause of their powerful activity has remained unknown. However, new research led by scientists from the Universities of Sheffield and Hertfordshire used deep imaging observations from the Isaac Newton Telescope in La Palma to identify distorted structures in the outer regions of the galaxies that contain quasars. These distortions were evidence of galactic collisions that were driving gas towards the black hole at the galaxy’s center. Just before the gas is consumed by the black hole, it releases extraordinary amounts of energy, resulting in the characteristic quasar brilliance.
By comparing observations of 48 quasars and their host galaxies with images of over 100 non-quasar galaxies, the researchers concluded that galaxies hosting quasars are approximately three times more likely to be interacting or colliding with other galaxies. This new understanding of how quasars are triggered and fueled is a significant step forward in astrophysics. The ignition of a quasar can have significant consequences for entire galaxies, including driving the rest of the gas out of the galaxy, which prevents it from forming new stars for billions of years into the future.
Quasars are important to astrophysicists as they act as beacons to the earliest epochs in the history of the universe due to their brightness. The discovery of the cause of quasar activity will help scientists understand the earliest galaxies in the universe better. Additionally, the ignition of quasars can provide insights into the future of the Milky Way galaxy when it collides with the Andromeda galaxy in about five billion years. However, it is essential to note that Earth will not be near any of these apocalyptic episodes for quite some time.
Source: University of Sheffield