In the boundless expanse of the Universe, where time is measured in billions of years, an epic battle between two galaxies has unfolded. Thanks to the powerful ALMA and ESO telescopes, scientists have recorded for the first time how one of them is using a quasar – super-powerful radiation from a black hole – to sabotage its rival to give birth to new stars. The results of the study, published in Nature, reveal one of the most brutal acts of intergalactic impact.
“We have observed a quasar that radically changes the gas structure of a neighboring galaxy. The photo is like a frozen frame of cosmic aggression,” explains Pasquier Noterdaeme of the Paris Astrophysical Institute, one of the study’s authors.
Galaxies at the crime scene
The event, which light traveled over 11 billion years, shows the Universe at its earliest period, when it was only 18% of its present age. In the images, the galaxies appear static, but they are moving towards each other at breakneck speeds of more than 500 km/s.
The quasar, an active galactic nucleus powered by a supermassive black hole, released a stream of energy that broke through the gas clouds of a neighboring galaxy. This “cosmic spear” scattered the matter needed to form stars, effectively paralyzing star formation.
“For the first time in history, we see how quasar radiation directly destroys the internal structure of a galaxy,” emphasizes Sergei Balashev of the Ioffe Institute.
However, the aggressor is also transformed by the interaction. Gravitational forces drive the gas toward the quasar’s black hole, increasing its activity. Thus, the conflict accelerates the evolution of both galaxies, but with different consequences: one loses future stars, the other gains fuel for new outbursts.
Technologies unlocking the past
ALMA’s high resolution allowed us to distinguish between two galaxies previously thought to be a single object. The ESO spectrograph helped analyze the effect of radiation on the chemical composition of the “victim”.
In the future, scientists plan to study such space battles with the Extremely Large Telescope (ELT). This will provide clues to understanding how quasars formed galaxies at the dawn of the Universe – and how they destroyed them.
Earlier we reported on where new stars were being born quickly.
According to ESO
