Znak Politechniki Warszawskiej

Black hole

Black hole image, Event Horizon Telescope

Black hole image, Event Horizon Telescope

WUT graduate involved in a breakthrough astrophysics project

Maciej Wielgus, PhD, Eng., was among 200 scientists from all over the world who helped capture the first-ever image of a black hole. In the course of the project, he was responsible for statistical data validation and bias modelling. He also focused on algorithms for data calibration and polarisation as well as on temporal variation of observed sources. Since June 2017, our graduate has been working for the Black Hole Initiative – an interdisciplinary centre at Harvard University. It is the first research centre in the world dedicated solely to black hole research.

“I was awarded a Black Hole Initiative Postdoctoral Fellowship with the Event Horizon Telescope (EHT)”, says Maciej Wielgus. “The project needed a scientist with expertise in the technical aspects of interferometry and an understanding of the theory of general relativity. Before, I had been involved in optical interferometry research at WUT’s Institute of Micromechanics and Photonics as well as projects concerning relative astrophysics at the Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences in Warsaw. This unusual combination turned out to be my ticket to the EHT project.”

How was the image of a black hole captured?

The Event Horizon Telescope was designed to monitor and study two supermassive black holes: one of them located in the centre of the Milky Way and the other in the centre of the Messier 87 galaxy. Over 200 researchers form several dozen countries were involved in the project.

Data needed to generate the first photo of a black hole were collected by means of a virtual telescope (i.e. a globe-spanning network of radio dishes) and processed using a technique called very long baseline interferometry (VLBI). The end result was achieved with data from the 2017 observation campaign by eight telescopes located in Europe, Latin America, Middle America, North America, Hawaii and the South Pole. All observations were collectedat a wavelength of 1.3 mm.

New research opportunities

The photograph presented on 10 April 2019 shows a black hole at the centre of Messier 87, a galaxy 55 million light-years away from Earth. The black hole has a mass 6.5 billion times that of the Sun.

“Even though the image is not, strictly speaking, a photograph, as it was obtained through radio interferometric imaging (which in fact is closer to holography than classic photography), currently it is the strongest evidence that supermassive black holes are central engines of galaxies, with their surroundings radiating enormous quantities of energy and generating astrophysical jets (beams of ionised matter)”, Wielgus explains.

These results open up new opportunities in the field of black hole research, making it possible to push gravity theory tests to the extreme, as black holes are spacetime objects with the strongest gravitational field – too powerful for even light to escape.

Maciej Wielgus, PhD, Eng., holds a MSc degree in robotics and automatic control from Warsaw University of Technology Faculty of Mechatronics. He received his PhD degree from Warsaw University of Technology Institute of Micromechanics and Photonics in 2016 for his thesis “Algorithms for adaptive processing of interferometric fringe patterns” written under the guidance of Prof. Krzysztof Patorski, PhD, D.Sc., Eng. In 2017, his doctoral dissertation received the Prime Minister’s distinction.

 

Agnieszka Kapela

Promotion and Information Office