For the first time, astronomers observed in the same image the shadow of a black hole at the center of the galaxy Messier 87 (M87) and the powerful jet ejected from it. Thanks to this image, they can better understand how black holes can shoot these jets. The relevant publication, in which a researcher from the Technology and Research Foundation in Crete participates, is presented in the journal “Nature”.

Most galaxies have a supermassive black hole at their center. While black holes are known to gobble up matter in their immediate vicinity, they can also eject powerful jets of matter that extend beyond the galaxies in which they live. Understanding how black holes create such massive jets is a long-standing question in astronomy.

The new image shows for the first time just that: how the base of a jet is attached to matter swirling around a supermassive black hole six and a half billion times the mass of the Sun. The black hole is located in the M87 galaxy, 55 million light-years away.

Image of the jet and shadow of the black hole in the galaxy M87. Credit: R.-S. Lu (SHAO), E. Ros (MPIfR), S. Dagnello (NRAO/AUI/NSF)

As Carolina Kassantiou, a researcher at the Institute of Astrophysics of the Foundation for Technology and Research and the Department of Physics of the University of Crete, who participates in the publication, points out to APE-MPE, “the mechanism of launching strong relativistic jets from the environment of voracious supermassive black holes, which lie at the center of active galaxies, continues to puzzle the astrophysical community.”

“With this new image of M87,” explains Ms. Cassandio, “we observe for the first time the connection between the jet and the emission region surrounding the black hole. This adds an important new element to solving the mystery of the jet launcher.”

This particular black hole was first imaged by the Event Horizon Telescope (EHT) in 2017, but the image released today shows radio light emitted at a longer wavelength than the EHT image. “At this wavelength we can see how the jet emerges from the emission ring around the central supermassive black hole,” notes Thomas Krickbaum of the Max Planck Institute for Radio Astronomy.

NASA

An artist’s impression of the black hole in the galaxy M87 and its powerful jet. Credit: S. Dagnello (NRAO/AUI/NSF)

Also, the size of the ring seen today is about 50% larger compared to the previous image, and computer simulations done for the research suggest that the new image reveals more material falling towards the black hole than would could be observed with EHT.

The observations of the present research were made in 2018 with three different groups of telescopes, GMVA located in Europe and North America, ALMA in the Atacama Desert of Chile, in which the European Southern Observatory (ESO) also collaborates, and GLT in Greenland. It is pointed out that in order to correctly capture the true shape of an astronomical object it is important that the telescopes are scattered all over the Earth. Future observations with this network of telescopes will continue to reveal how supermassive black holes can shoot powerful jets.