26 September 2017

PhD graduate at the Institute of Astrophysics UC publishes article on the evolution of binary black holes

Felipe Garrido Goicovic, who recently defended his doctoral thesis, wrote an interesting paper that presents a new mechanism for the evolution of binary systems of super-massive black holes.

icsSuper-massive black holes, as their name suggests, are black holes that have a mass greater than a million suns, found in the centers of galaxies. In fact, they are fundamental for galaxy evolution because they emit large amounts of energy when they feed on material. Felipe Garrido Goicovic, recently graduated from the UC Institute of Astrophysics, has studied the evolution of binary systems of super-massive black holes for several years. "During their life, galaxies merge with each other to form new ones. Therefore, it is inevitable that their black holes meet and orbit each other, forming a binary system."

At the present time, he says, there is little observational evidence of these systems and the mechanisms that lead the binary system to its fusion. "I investigate the evolution of molecular gas clouds as they approach and are captured by binary super-massive black holes. This new paper presents the results of thirteen simulations developed to study the evolution of the binary's orbit as a function of the trajectory of the clouds. With the results of the simulations, we build a simple model to 'evolve' a binary and find the time scale on which the black holes would merge".

The results of his research show that the binary would merge within a few hundred million years only, "suggesting that cloud infall to the centers of galaxies could be an important mechanism in the evolution of these binaries".

The next step, he says, is to develop simulations where we model the interaction of a binary with a sequence of clouds (unlike the study to be published, where it was simulated with individual clouds), "that will allow us to compare directly with the simplified model and thus to separate the effect that the cloud has when impacts directly on the binary from the effect of the material that accumulates around it."

The research will be published on the Monthly Notices of the Royal Astronomical Society, and was part of Felipe's PhD thesis that started in 2013 and was successfully defended in August this year. Felipe is now working as a postdoctoral researcher at the Institute for Theoretical Studies in Heidelberg (HITS), Germany.

You can view the paper here.