Mystery of quasars' terrifying power finally solved

  Headed by researchers from the UK's Sheffield and Hertfordshire universities, an international group of experts has unraveled one of astronomy's most enigmatic questions: the source of quasars' exceptional power. Quasars, the universe's most luminous and energetic entities, were first detected 60 years ago. Their brightness is so incredible that it would take a trillion stars packed into a space the size of our solar system to equal it. While it is known that the tremendous energy emitted by a quasar is related to the activity of supermassive black holes at the center of many galaxies, the precise trigger for such a powerful reaction has remained unknown. Recently published in the 'Monthly Notice of the Royal Astronomical Society,' the new research, which includes contributions from Spanish astrophysicist C. Ramos Almeida of the University of La Laguna, reveals that quasars result from galaxy collisions.

The team made this discovery by using deep imaging observations from the Isaac Newton Telescope at Palma to detect distorted structures in the outer areas of galaxies hosting quasars. Most galaxies have supermassive black holes at their cores and are filled with vast amounts of gas. However, this material typically orbits far from the galactic centers, beyond the reach of black holes. Galaxy collisions alter this situation by driving the gas toward the center and into the clutches of the black hole, which then consumes it in massive quantities. This process causes the black hole to emit extraordinary levels of radiation, giving rise to the powerful phenomenon known as quasars.

Quasar ignition is a significant event, potentially expelling a galaxy's entire gas supply into space and halting new star formation for billions of years. Currently, approximately 200,000 quasars are known to exist, all at considerable distances from the Milky Way. Nonetheless, when our galaxy collides with the approaching Andromeda galaxy in around five billion years, it is expected to create its own quasar, visible throughout the universe.

Clive Tadhunter from the University of Sheffield and co-author of the study, explains, "Quasars are among the universe's most extreme phenomena, and what we've observed likely represents the future of our own galaxy, the Milky Way, when it collides with the Andromeda galaxy in about five billion years. It's thrilling to witness these events

 Source