Stars can’t hide behind the light from feeding supermassive black holes in the infant universe any longer.
With help from the James Webb Space Telescope (JWST), astronomers have seen starlight from two early galaxies hosting supermassive black holes, or quasars, for the first time. The findings could eventually help scientists better understand how supermassive black holes grow rapidly to masses equivalent to millions or billions of suns and how they evolve along with the galaxies that host them.
“25 years ago, it was surprising to us that we were able to observe host galaxies 3 billion years ago, using large ground-based telescopes,” said team member and Max Planck Institute researcher for Astronomy Knud Jancke. he said in a statement. “The Hubble Space Telescope allowed us to explore the peak era of black hole growth 10 billion years ago. And now we have the JWST available to see the galaxies where the first supermassive black holes appeared.”
Related: Cosmic monsters lurking at the core of ancient star clusters have been found by the James Webb Space Telescope
The team observed two of these so-called active galaxies, which are seen as they were when the 13.8-billion-year-old universe was less than a billion years old. They were able to calculate both the mass of the galaxies and the mass of the supermassive black holes that power the quasars, designated J2236+0032 and J2255+0251. The light from these two galaxies took 12.9 and 12.8 billion years to reach us, and so appeared to astronomers as they were 870 and 880 million years later. Big Bang, respectively.
Observations revealed that the mass of the galaxies is 130 billion 30 billion times that of the Sun, and that the monster feeding the black holes has masses of 1.4 billion solar masses for J2236+0032 and 200 million solar masses for J2255+0251. This showed that the mass of these early galaxies and their black holes The central is related in the same way as seen in the galaxies observed near the Milky Way, and is therefore more recent in time.
How do supermassive black holes grow with their galaxies?
Quasars are some of the most extreme objects in the entire universe. Powered by supermassive black holes surrounded by gas and dust, some accreting into the black hole, some exploding at speeds approaching the speed of light, quasars emit so much light that they can often outshine every star in the host galaxy combined.
Almost every galaxy is believed to have a supermassive black hole at its core, but not all of these stars are quasars. For example, the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), consumes so little matter as a human eating a grain of rice every million years. Thus, it is not feeding enough to power the quasar.
The first quasar was spotted in 1963, and since then, scientists have uncovered the processes powering their massive emission of light. In the 2000s, it was discovered that the masses of galaxies and their supermassive black holes are interconnected, with the mass of stars in a galaxy about 1,000 times greater than that of its central black hole.
The relationship between the masses of supermassive black holes and their galaxies holds true for galaxies with supermassive black holes millions of times the mass of the Sun, and for those with central black holes billions of times more massive than our star.
The relationship between the mass of galaxies and the mass of their supermassive black holes may be related to the fact that both grow through a series of intergalactic mergers that eventually lead to the black holes at the cores of those galaxies violently colliding with each other. creating a larger black hole. Thus, after many mergers, the mass of the galaxy will be about the average mass of the initial galaxy multiplied by the number of galaxies it merged with, while the mass of the central black hole will be about the mass of the initial black hole multiplied by the same number. , which leads to an approximately linear relationship.
Another suggestion is that when a supermassive black hole feeds off enough matter to become a quasar, the radiation that explodes marshals the matter available for both the quasar and the formation of new stars. And so when a quasar runs out of food and stops growing, star formation also slows down in that galaxy.
Whatever the reason for this relationship, astronomers have not been able to determine whether galaxies and their supermassive black holes existed in the very early universe until now. This is because, while the brightness of quasars allows them to be studied at distances billions of light-years away, it also makes observing the dim starlight from the quasars’ host galaxies difficult.
Ground-based telescopes struggle to distinguish light from quasars and light from stars in their galaxies due to the influence of Earth’s atmosphere. From its position above the atmosphere, the Hubble Space Telescope has had some success detecting light from these galaxies when they are about 10 billion light-years away. But to do that in galaxies older and more distant, astronomers had to wait for the most powerful space telescope ever put into orbit, JWST.
The quasars J2236+0032 and J2255+0251 were observed using JWST’s primary instrument, the Near Infrared Camera (NIRCam), for two hours at two different wavelengths. The team took this combined spectrum of quasar and starlight for both galaxies, then separated the quasar light to see the light from early stars in such galaxies for the first time.
Remarkably, observations of J2236+0032 and J2255+0251 and their galaxies using JWST have shown that the black hole/super galaxy cluster relationship existed even in the early universe. Currently, this data alone is not enough to reveal the origins of this collective relationship and how supermassive black holes grow to such gigantic sizes, but they will inform future investigations.
The results represent just a portion of JWST’s observations of distant quasars, as the powerful space telescope currently monitors ten of these massive black hole objects and their galaxies. In addition, another 11 hours of observation time was given for this specific exploration of the early universe.
The research was published June 28 in the journal Nature.
