New Detection Method Could Double the Number of Known Black Holes Within 2 Years

Researchers from the University of Waterloo are boldly combining two standard astrophysical tools to develop a new detection method that could double the number of known black holes within two years and could also unlock the history of black holes in a little more than a decade.

The new method, described in a paper published in the Astrophysical Journal, showed that using radio wave interferometry and microlensing could detect and study black holes in large numbers as a system, as opposed to studying them as single entities.

"Within the next 10 years, there will be sufficient accumulated data on enough black holes that researchers can statistically analyze their properties as a population," said Avery Broderick, a professor in the Department of Physics and Astronomy at the University of Waterloo and associate faculty member at the Perimeter Institute for Theoretical Physics, in a press release. "This information will allow us to study stellar mass black holes at various stages that often extend billions of years."

For the new method, the researchers proposed using radio wave interferometry to take multiple snapshots of microlensing event in real time, Astronomers have been using gravitational microlensing to observe distant and dark objects. When a dark object passes between the Earth and another light source, the light from the source bends around the object's gravitational field to reach Earth. This makes the background light source appear much brighter. However, microlensing events observed invisible light only have limited resolution, even with the used of the largest telescope.

With the proposed method, the astronomers would look into multiple snapshots of microlensing event using radio waves. By looking at the same event using radio telescope, astronomers could resolve more than one image. This gives them the power to extract all kinds of parameters to further understand black holes, including the black holes' mass, distance and velocity.