Funding of 1.7 million euros to a Greek astrophysicist for research on supermassive black holes

Maria Harisi received an ERC Starting Grant, awarded to talented young scientists who have already done outstanding work and have the potential to become leaders in their scientific field.

The researcher from Vanderbilt University in the United States and soon to be assistant professor of physics at Washington State University, has been selected for funding from the very competitive ERC Starting Grant program of the European Research Council.

ERC Starter Grants are awarded to talented young scientists who have already done outstanding work and have the potential to become leaders in their scientific field. Maria Harisi will receive funding of 1.7 million euros over five years to create a research team at the Institute of Astrophysics of the Institute of Technology and Research (ITE) with the aim of detecting, for the first times, binary systems of supermassive black holes, which emit gravitational waves.

Binary supermassive black holes are thought to form frequently in the Universe when galaxies collide, because every massive galaxy has a supermassive black hole at its center, with a mass ranging from a few million to a few billion times that of the Sun. . However, after decades of research, these systems cannot be detected by scientists.

However, their detection constitutes a crucial step in understanding how galaxies and the supermassive black holes located at their hearts form and evolve. At the final stage of their evolution, these binary systems emit very intense electromagnetic radiation and can be detected as quasars (a type of extremely bright galaxy), whose brightness changes periodically.

At the same time, they also emit low-frequency gravitational waves that can be observed by a galactic-sized detector given to us “free” by the Universe itself. It is the famous pulsars, the spinning neutron stars, which are nature’s most precise clocks.

Astronomers have developed techniques to analyze the pulses sent by all these pulsars together, with a method called pulsar synchronization array. As gravitational waves propagate through the Universe and pass through the region where the pulsars are, they slightly change their distance from Earth, thus changing the arrival time of their pulses, allowing us to determine the wider region from which they originate.

Maria Harisi’s ERC program, by combining these measurements with observations of the variability of all the quasars located in this same region, aims to identify the binary system that emits the gravitational waves. To this end, the team will develop new machine learning techniques and apply them to data from several telescopes, including the new Vera Rubin telescope in Chile, which will begin operating from 2024, as well as data waves from gravitational detection of pulsar synchronization networks. whose sensitivity is constantly improving.

It should be noted that the Foundation for Technology and Research has the highest number of ERC-funded projects (40) in Greece. In particular, the Institute of Astrophysics of ITE, despite its small size (it has only 5 researchers and 4 collaborating professors from the University of Crete), hosts 4 of the 5 awarded ERCs in the thematic area of astronomy in Greece. This fact is proof of the international recognition of the quality of the research carried out at the ITE.

Who is the Greek researcher?

Maria Harisi graduated from the Physics Department of the Aristotle University of Thessaloniki. She continued her studies in astronomy at Columbia University in New York. She received her PhD in 2017 and performed one of the first studies to detect supermassive black hole binary systems using electromagnetic telescope observations.

She then continued her postdoctoral research at the California Institute of Technology (Caltech) in Los Angeles thanks to a grant from the scientific group NANOGrav (North American Nanohertz Observatory for Gravitational Waves), where she had the opportunity to expand her research to the study of gravitational phenomena. waves emitted by dual systems. He now works as a postdoctoral researcher at Vanderbilt University in Nashville, where he pioneered the combination of data from electromagnetic and gravitational waves.

He is an active member of international collaborative groups such as NANOGrav, the International Pulsar Timing Array and the LISA Telescope Team. She will continue her research in the rapidly developing field of “multi-messenger astronomy”, at the Institute of Astrophysics of the ITE.