Israeli astronomers have discovered an enigmatic supermassive black hole from the Universe's youth, shrouded in cosmic dust, using data from the James Webb Space Telescope (JWST), a discovery that calls into question how astrophysicists understand the growth of black holes and their relationship to galaxies where he is, the TPS agency reports on Tuesday.
Black hole PHOTO: Archive
The James Webb telescope is an observatory placed in an orbit 1.5 million kilometers from Earth, offering scientists an unprecedented perspective on the most distant cosmic objects and on some unknown phenomena in the Universe, writes Agerpres.
Analyzing images obtained by means of JWST, a team of astronomers coordinated by Dr. Lukas Furtak and Prof. Adi Zitrin from Ben-Gurion University of the Negev, identified what appeared to be a quasar-like object from the youth of the Universe. Quasars are very bright galactic nuclei powered by supermassive black holes that feed on the surrounding matter.
The matter that is accelerated into the black hole emits huge amounts of radiation, the accretion disk formed around the black hole being brighter than the entire host galaxy.
“Three very compact objects with a reddish glow stood out”, said Furtak, who also coordinated the study accompanying this discovery. Their reddish appearance made us believe that it is a cosmic object of the quasar type.
But this black hole was active and was swallowing matter that had accumulated around it forming an accretion disk. This matter can come from various sources, such as cosmic gas clouds, stars or even other black holes, according to Zitrin.
These data were obtained as part of the UNCOVER research program, in which the James Webb telescope was used to observe the galaxy cluster Abell 2744 at an unprecedented depth.
The Israeli researchers used a numerical lensing model built for the galaxy cluster and concluded that the three reddish objects are actually images of the same background source, seen in images obtained by the James Webb telescope as it was when the Universe was age of about 700 million years.
Researchers from Ben-Gurion University work within the UNCOVER research program, where they collaborate with scientists from the US and Australia. They were able to confirm that the compact reddish cosmic object observed by JWST is a supermassive black hole and precisely measured its redshift (a redshift occurs when the light source moves away from the observer). They were also able to formulate an estimate of the black hole's mass from analysis of its spectral emission lines, according to Furtak.
The cosmic gas orbits the gravitational field of the black hole, reaching very high speeds that have not been observed in other parts of the galaxies. Because of the Doppler effect, the light emitted by the matter in the accretion disk around the black hole is redshifted on one side and blueshifted on the other side, according to its speed. Because of this, the emission lines in the spectrum become wider, he explained.
According to the researchers, the colors suggest that the black hole is behind a thick curtain of cosmic dust, which hides much of the brightness of its accretion disk. The team managed to measure the mass of this black hole and concluded that it is at least 1% of the total mass of the galaxy it is part of, being significantly heavier compared to the galaxy at its center by comparison with other supermassive black holes at the center of other galaxies, according to Jenny Greene, professor at Princeton University and co-author of the study presented in the latest issue of the journal Nature.
The study of this black hole is a piece of the puzzle regarding the appearance and evolution of the first galaxies and supermassive black holes in the Universe. Astronomers still do not know whether such supermassive black holes from the young Universe were born from stellar remnants or clumps of matter so large that they could collapse directly to form black holes.
“In a way, it's the astrophysical equivalent of the chicken and the egg problem. We don't yet know which formed first – the galaxy or the black hole, nor how massive the first black holes were or how they grew.”Prof. Zitrin also claimed.
