California Institute of Technology | 2020 Jun 25
Possible light flare observed from small black holes within the disk of a massive black hole
When two black holes spiral around each other and ultimately collide, they send out ripples in space and time called gravitational waves. Because black holes do not give off light, these events are not expected to shine with any light waves, or electromagnetic radiation. But some theorists have come up with ways in which a black hole merger might explode with light. Now, for the first time, astronomers have seen evidence for one of these light-producing scenarios.
- Artist's concept of a supermassive black hole and its surrounding disk of gas. Embedded within this disk are two smaller black holes orbiting one another. Using data from the Zwicky Transient Facility (ZTF) at Palomar Observatory, researchers have identified a flare of light suspected to have come from one such binary pair soon after they merged into a larger black hole. ... These merging black holes were first spotted on May 21, 2019, by LIGO and Virgo... Credit: Caltech/R. Hurt (IPAC)
With the help of Caltech's Zwicky Transient Facility (ZTF), funded by the National Science Foundation (NSF) and located at Palomar Observatory near San Diego, the scientists have spotted what might be a flare of light from a pair of coalescing black holes. The black hole merger was first witnessed by the NSF's Laser Interferometer Gravitational-wave Observatory (LIGO) and the European Virgo detector on May 21, 2019, in an event called S190521g. As the black holes merged, jiggling space and time, they sent out gravitational waves.
While this was happening, ZTF was performing its robotic survey of the sky that captured all kinds of objects that flare, erupt, or otherwise vary in the night sky. One flare the survey caught, generated by a distant active supermassive black hole, or quasar, called J1249+3449, was pinpointed to the region of the gravitational-wave event S190521g. ...
Possible Flare from Black Hole Merger
APS Physics Focus | 2020 Jun 25
Candidate Electromagnetic Counterpart to the Binary Black Hole
Merger Gravitational-Wave Event S190521g ~ M. J. Graham et al