James Webb telescope helped detect stars in very distant quasars for the first time
(Xuheng Ding et al. / arXiv, 2022 https://bit.ly/3hRyXJa)
The James Webb Space Telescope (JWST) has seen stars in very distant quasars for the first time.
Their light took 13.43-13.56 billion years to reach the Earth.
The results of the observations will help to understand the mechanisms of the rapid growth of supermassive black holes in the early Universe.
The detection of supermassive black holes in quasars that existed in the first billion years of the life of the Universe is one of the main problems of modern astrophysics.
Right now there is no generally accepted theory explaining the mechanisms of formation and rapid growth of the mass of these objects.
Data on the parameters of distant supermassive black holes and their host galaxies can help test the existing hypotheses,
However, for a long time it was extremely difficult to detect the stellar population in the host galaxies of quasars at redshifts z greater than two.
THE OBSERVATION
Now, astronomers at the Kavli Institute of Physics and Mathematics reported that for the first time they were able to observe the stellar population of quasar host galaxies at redshifts z greater than 6.
Those are the quasars J2255+0251 and J2236+0032, which are characterized by relatively low luminosities and redshifts z equal to 6.34 and 6.4, respectively.
Initially, the quasars were discovered by the Subaru ground-based telescope as part of the SHELLQ (Subaru High-z Exploration of Low-luminosity Quasars) survey of dim quasars.
However, their further study was hampered by the low brightness of objects in the infrared range.
In the current work, the team led by Xuheng Ding used the NIRCam instrument in the JWST to observe the area in near infrared range on October 26 and November 6, 2022.
Ding’s team then ran a series of simulations to separate the emission from the quasar's host galaxy from that of the quasar itself, whose active core contains a supermassive black hole.
In the case of J2255+0251, its host galaxy has a disc-shaped with an effective radius of 1.9 kiloparsecs.
In the case of J2236+0032, its host galaxy has a slightly inclined disk-like profile with an effective radius of 0.6–0.8 kiloparsec.
The stellar masses of galaxies are estimated at 2.5 and 6.3×1010 solar masses, making them massive objects.
It is worth noting that, unlike most supermassive black holes in the Local Universe, the observed quasars are spatially displaced from the centers of their host galaxies.
Sources:
- Arxiv: https://arxiv.org/abs/2211.14329
- Phys.org: https://phys.org/news/2022-12-astronomers-stars-distant-galaxies.html
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