The fusion of monster black holes can be common

The spiral galaxies UGC 9618 and VV 340, which are about to collide. Astronomers believe that these galaxy fusions also typically involve the fusion of supermassive black holes in the heart of galaxies.
(NASA, ESA, Hubble Heritage (STScI / AURA) – ESA / Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville / NRAO / Stony Brook University))

A new study suggests that the collision of black holes harboring millions or billions of times the mass of the sun is common in the universe.

Such supermassive black holes are hidden in the heart of most, if not all, galaxies, including our own Milky Way. Galaxy fusions are common in the universe and astronomers believe that such mashups usually involve the fusion of gigantic central black holes.

But the evidence of such collisions has been elusive to this day. For example, the gravitational waves emitted in the period before monster black hole mergers are probably outside the range of those detectable by the Laser Interferometer Gravitational Wave Observatory (LIGO). The gravitational waves detected by LIGO to date have been emitted by the fusion of objects sheltering only a few tens of solar masses. [Hunting Gravitational Waves: The LIGO Laser Interferometer Project in Photos]

Thus, in the new study, researchers took a different approach. They analyzed the radio wave length observations of 33 strong jet sources, features typically associated with supermassive black holes. In 24 of these sources, the team noted signs of "precession" or a change in orientation of the axis of rotation.

This was a surprise, said senior author of the study, Martin Krause, of the University of Hertfordshire in England.

"We have been studying jets under different conditions for a long time with computer simulations," Krause said in a statement. "In this first systematic comparison to the high-resolution radio maps of the most powerful radio sources, we were surprised to find signatures compatible with the precession of the jets in three quarters of the sources."

This apparent precession signature is consistent with the existence of supermassive binary and super-orbiting black holes pulling one over the other, team members said. study. And this binary step is probably not the last, but rather the precursor of a next merger, they added.

Detecting gravitational waves from these sources will likely be difficult in the near future, the researchers wrote in the study, published today (23 October) in the Royal Astronomical Society's Monthly Notices.

"The independent confirmation of our sub-parsec binary supermassive black hole candidates, and indeed of any extragalactic jet source with some evidence of geodesic precession, via individual gravitational wave detections will be difficult," wrote the members of l & # 39; team. "Thus, improving the modeling of the jet-environment interaction for jet precession sources is probably the best way to better constrain powerful objects in the coming years."

You can read a copy of the document for free at the arXiv.org online pre-print site.

Originally published on Space.com.