Using the NASA/ESA/CSA James Webb Space Telescope, astronomers observed a very red quasar-like object. A2744-QSO1 Its color suggests that A2744-QSO1's black hole lies behind a thick veil of dust obscuring much of its light. The researchers also measured the black hole's mass (40 million solar masses) and found it to be much more massive compared to its host galaxy than what has been seen in more localized examples. . This discovery suggests that it may represent the missing link between black hole seeds and the first luminescent quasars.
A composite color image of A2744-QSO1. Image credit: Furutaku other, doi: 10.1038/s41586-024-07184-8.
“We were very excited when Webb started transmitting its first data,” said Dr. Lukas Furtak, a postdoctoral researcher at Ben-Gurion University of the Negev.
“As we were scanning the data coming in for the UNCOVER program, three very compact objects with red flowers stood out to us.”
“Because of its 'red dot' appearance, we immediately suspected it to be a quasar-like object.”
“Using a numerical lensing model we built for the Abell 2744 galaxy cluster, we found that the three red dots are multiples of the same background light source seen when the universe was just 700 million years old. “We determined that it must be an image of Adi Zitlin, also from Ben-Gurion University in the Negev.
“Analysis of the object's color shows that it is not a typical star-forming galaxy,” said Professor Rachel Bezanson, an astronomer at the University of Pittsburgh.
“This further supports the supermassive black hole hypothesis.”
“Together with its compact size, it became clear that this was probably a supermassive black hole, but it was still different from other quasars discovered earlier.”
The astronomers then analyzed the JWST/NIRSpec spectrum of A2744-QSO1.
“The spectrum was just shocking,” said Professor Ivo Rabe of Swinburne University of Technology.
“The spectrum obtained by combining the signals from the three images and the lens magnification corresponds to 1,700 hours that Webb observed the object without a lens, making it the deepest spectrum Webb obtained for a single object in the early universe. Masu.”
“Using the spectrum, we were able to not only confirm that this red compact object is a supermassive black hole and measure its precise redshift, but also estimate its mass based on the width of its emission line. We were able to get a solid estimate,” Dr. Furtak said.
“The gas orbits the black hole's gravitational field, achieving extremely high velocities not seen in other parts of the galaxy.”
“Due to the Doppler shift, the light emitted from the accreting material is redshifted on one side and blueshifted on the other side, depending on its velocity.”
“This makes the emission lines in the spectrum wider.”
But this measurement brought yet another surprise. The black hole's mass appears to be disproportionately large compared to the mass of its host galaxy.
“All the light in that galaxy would have to fit within a small region about the size of a modern star cluster,” said Dr. Jenny Green, an astronomer at Princeton University.
“The source's gravitational lensing magnification provided an exquisite constraint on size.”
“Even if you pack all possible stars into such a small region, the black hole will end up being at least 1% of the total mass of the system.”
“In fact, it has now been discovered that several other supermassive black holes in the early Universe exhibit similar behavior, which provides insight into the growth of black holes and host galaxies, and the interactions between them. This provides some interesting insights, but this is not well understood.”
Astronomers do not know whether such supermassive black holes grow from the remains of stars, for example, or perhaps from material that collapsed directly into black holes in the early universe.
“In some ways, this is an astrophysical chicken-and-egg problem,” says Professor Zitlin.
“Currently we don't know whether galaxies or black holes formed first, how big the first black holes were, and how they grew.”
“Recently, many more such 'little red dots' and other active galactic nuclei have been detected in the Webb, so we hope to have a better idea soon.”
of the team result appear in the diary Nature.
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LJ Furutak other. High black hole-to-host mass ratio in the lensed AGN of the early Universe. Nature, published online on February 14, 2024. doi: 10.1038/s41586-024-07184-8
