How do supermassive black holes become monstrous in size in a relatively short period of time? A new study from researchers in Italy suggests an answer.

Whilst astronomers are fairly certain that supermassive black holes, billions of times more massive than our Sun, dwell at the centre of almost every galaxy in the Universe, they are still unsure how these cosmic monsters reach such tremendous sizes.

The problem seems to be one of time, the Universe is 14 billion years old, and recent observations seem to confirm that such black holes were already present when it was just 800 million years old — thus in its relative infancy. How could these black holes have accrued so much matter to supermassive status in such a, relatively, short space of time?

According to classical theories, these space giants would not have had the time to develop in the young Universe. Yet, observations say they were already present. A new study by SISSA proposes a response to the fascinating question (NASA/JPL-Caltech)

This lingering question poses a problem for our very understanding of the evolution of such spacetime events. Now, a paper published in The Astrophysical Journal suggests an answer. Authors Lumen Boco, a PhD student, and his supervisor Andrea Lapi, coordinator of the Astrophysics and Cosmology group at Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy, use a model initially theorized by colleagues to suggest a very fast formation process in the initial phases of the development of the supermassive black holes.

The team’s work suggests that supermassive black holes grow rapidly due to the merging of stellar compact remnants like neutron stars and smaller stellar-mass black holes.

The team’s results seem to confirm mathematically that supermassive black holes could have existed in the early Universe shortly after the big bang, reconciling the timing required for such rapid growth with the constraints arising from the age of the Universe.