2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Images of the quasar PSO167-13 in the optical, X-ray and radio wavelength ranges.
Astronomers using ground and space observatories were able to discover the first candidate for hidden quasars in the early universe. We see it as it was when the universe was only 850 million years old. If this is confirmed in the future, then the quasar will become a record object of this type in terms of distance from the Earth and will help test the theory of the formation and growth of supermassive black holes. The article was published in the journal Astronomy & Astrophysics Letters.
The fact of the discovery of black holes with masses of 109-1010 solar masses, which actively absorb matter and are located in the center of 180 bright quasars, at redshifts z> 6, strongly influenced the theory of the formation and growth of supermassive black holes in the early Universe - this problem is one of the main in modern astrophysics. There are several different explanations for the formation of the embryos of such objects. The two most popular classes of models predict the formation of "light nuclei" (about 100 solar masses) from the remnants of Population III stars and "heavy nuclei" (from 104-106 solar masses) during the direct collapse of giant primordial gas clouds. All these models require a continuous rate of accretion of matter onto a black hole, which can be comparable to or exceed the Eddington limit, and the black hole itself will be practically hidden from an external observer by large volumes of dense accreting matter. Such situations can arise during the merger of galaxies, but it is extremely difficult to detect such "hidden" quasars due to the absorption of most of the radiation by matter emanating from the region of a supermassive black hole.
A group of astronomers led by Fabio Vito announced the discovery of the first candidate for hidden quasars in the early Universe, designated PSO 167-13. The object was initially detected by the Pan-STARRS optical system and included in the list of quasar candidates at high redshifts, then this was confirmed by observations made with the ALMA radio telescope system in line [C II]. Subsequently, the Hubble Space Telescope and the Chandra Observatory were connected to the observations.
Images of the quasar PSO167-13 obtained by the Hubble telescope and the ALMA /
It turned out that the position of the quasar candidate correlates with the position of the optically distinguishable galaxy PSO 167-13 at z = 6.515, next to which there is another galaxy at a distance of about five kiloparsecs. Chandra's data show that the newly discovered object is a source of high-energy X-ray quanta, but very few of them were recorded over 16 hours of observations. This can be explained by the absorption of X-ray radiation by dense gas clouds surrounding the central region of the quasar. Regardless of which galaxy is the source of X-ray quanta, the entire pair represents the first candidate for hidden quasars in the early universe. If this is confirmed in the future, then PSO167-13 will become a record object of this type in terms of distance.
Earlier, we talked about a quasar, the light from which traveled to Earth for more than thirteen billion years, how a gravitational lens helped measure the rotation of supermassive black holes, and how astronomers discovered "transitional" quasars.
