These objects roam the Universe freely and are hidden, experts say

Mar 13, 2014 21:51 GMT  ·  By

A group of experts from the Harvard University, led by astrophysicist Avi Loeb and graduate student Xiawei Wang, argues in a new study that they have developed a new method to detect rogue black holes. These objects are hypothesized to exist, but they have never been identified with precision. 

Unlike their massive or supermassive counterparts, rogue black holes do not lie at the cores of large galaxies similar to the Milky Way. As such, their location cannot be identified based on large-scale spacetime distortions or by the wobbles they produce in the orbits of nearby stars and gas clouds.

What is truly troublesome is that one of these objects may enter the solar system without us even knowing it until it is too late. As such, astronomers have recognized the need to develop an accurate method of identifying these structures long ago. Loeb's team may have finally achieved this objective.

According to some statistics, several hundreds of these rogue black holes may permeate the Milky Way. By identifying and studying these objects, researchers hope to gain additional knowledge of how galactic formation occurred in the earlier Universe. At this point, our best theory is that the Milky Way was assembled through numerous collisions of smaller, dwarf galaxies.

Rogue black holes are believed to be a remnant of those early cosmic times, the cores of the dwarf galaxies that have long since been incorporated into our own. Each of these objects is estimated to tip the scales at between 1,000 to 100,000 solar masses. Scientists hope to soon use these structures similarly to how paleontologists use fossils to find out more about Earth's distant past.

“The Milky Way halo serves as a kind of a ‘reservoir’ of wandering black holes that originally lived in the cores of the small galaxies that merged to make it,” Loeb explains. “When such black holes pass through the gas disk of the Milky Way galaxy, they produce a bow shock – similar to the sonic boom produced in the air by supersonic jets,” he goes on to say.

“The shock accelerates electrons to high energies and these emit radio waves that we can detect,” Loeb explains. The next step in the study would be to actually test this hypothesis. More theoretical work is needed beforehand, so that theoreticians can determine via calculations the nature of these radiations.

Loeb says that radio waves are the most likely candidates, meaning that they could be easily detected using existing radio telescopes. “Of course, if such a bow shock is discovered, one would be able to also observe the cluster of stars attached to the floating black hole and possibly the X-ray emission from the black hole itself as it accretes gas,” he explains.

The main problem facing this confirmation study today is that there are countless sources of radio and infrared radiations in the galactic halo, so establishing which of them is a rogue black hole could take a while, Space reports.