Monster colliding black holes might lurk on the edge of spiral galaxies

October 30, 2017

The outskirts of spiral galaxies like our own could be crowded with colliding black holes of massive proportions and a prime location for scientists hunting the sources of gravitational waves, said researchers at Rochester Institute of Technology in an upcoming paper in Astrophysical Journal Letters.

The RIT study identifies an overlooked region that may prove to be rife with orbiting black holes and the origin of gravitational-wave chirps heard by observatories in the United States and Italy. Identifying the host galaxies of merging massive black holes could help explain how orbiting pairs of black holes form.

Conditions favorable for black-hole mergers exist in the outer gas disks of big spiral galaxies, according to Sukanya Chakrabarti, assistant professor of physics at RIT and lead author of "The Contribution of Outer H1 Disks to the Merging Binary Black Hole Populations," available online at https://arxiv.org/abs/1710.09407.

Until now, small satellite or dwarf galaxies were thought to have the most suitable environment for hosting black-hole populations: a sparse population of stars, unpolluted with heavy metals like iron, gold and platinum -- elements spewed in supernovae explosions -- and inefficient winds that leave massive stars intact.

Chakrabarti realized the edges of galaxies like the Milky Wavy have similar environments to dwarf galaxies but with a major advantage -- big galaxies are easier to find.

"The metal content in the outer disks of spiral galaxies is also quite low and should be rife with black holes in this large area," Chakrabarti said.

A co-author on the paper, Richard O'Shaughnessy, assistant professor of mathematical sciences at RIT and a member of the LIGO Scientific Collaboration, said: "This study shows that, when predicting or interpreting observations of black holes, we need to account not only for differences between different types of galaxies but also the range of environments that occur inside of them."

A deeper understanding of the universe is possible now that scientists can combine gravitational wave astronomy with traditional measurements of bands of light. Existing research shows that even black holes, which are too dense for light to escape, have a gravitational wave and an optical counterpart, remnants of matter from the stellar collapse from which they formed.

"If you can see the light from a black-hole merger, you can pinpoint where it is in the sky," Chakrabarti said. "Then you can infer the parameters that drive the life cycle of the universe as a whole and that's the holy grail for cosmology. The reason this is important is because gravitational waves give you a completely independent way of doing it so it doesn't rely on astrophysical approximations."
-end-
Chakrabarti and O'Shaughnessy are members of RIT's Center for Computational Relativity and Gravitation. The center is a hub of multimessenger astronomy research and home to the Frontiers in Gravitational Wave Astronomy initiative, an RIT signature research area.

Rochester Institute of Technology

Related Black Holes Articles from Brightsurf:

The black hole always chirps twice: New clues deciphering the shape of black holes
A team of gravitational-wave scientists led by the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) reveal that when two black holes collide and merge, the remnant black hole 'chirps' not once, but multiple times, emitting gravitational waves--intense ripples in the fabric space and time--that inform us about its shape.

Black holes? They are like a hologram
Spherical, smooth and simple according to the theory of relativity, or extremely complex and full of information as, according to quantum laws, Stephen Hawking used to say?

Under pressure, black holes feast
A new, Yale-led study shows that some supermassive black holes actually thrive under pressure.

Staining cycles with black holes
In the treatment of tumors, microenvironment plays an important role.

Black holes sometimes behave like conventional quantum systems
A group of Skoltech researchers led by Professor Anatoly Dymarsky have studied the emergence of generalized thermal ensembles in quantum systems with additional symmetries.

Scientists may have discovered whole new class of black holes
New research shows that astronomers' search for black holes might have been missing an entire class of black holes that they didn't know existed.

Are black holes made of dark energy?
Two University of Hawaii at Manoa researchers have identified and corrected a subtle error that was made when applying Einstein's equations to model the growth of the universe.

Telescopes in space for even sharper images of black holes
Astronomers have just managed to take the first image of a black hole, and now the next challenge facing them is how to take even sharper images, so that Einstein's Theory of General Relativity can be tested.

Can entangled qubits be used to probe black holes?
Information escapes from black holes via Hawking radiation, so it should be possible to capture it and use it to reconstruct what fell in: if given time longer than the age of the universe.

How black holes power plasma jets
Cosmic robbery powers the jets streaming from a black hole, new simulations reveal.

Read More: Black Holes News and Black Holes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.