Breaking News: James Webb Space Telescope Discovers Ancient Galaxies with Massive Black Holes
September 4, 2023
The James Webb Space Telescope, operated by the Kavli Institute for the Physics and Mathematics of the Universe, has made a groundbreaking discovery, unveiling starlight from two ancient galaxies with quasars. These galaxies, observed less than a billion years after the Big Bang, contain black holes with masses nearly a billion times that of the Sun. This discovery raises questions about the formation sequence of supermassive black holes and galaxies in the early universe.
The images captured by the James Webb Space Telescope reveal, for the first time, the starlight emitted by two colossal galaxies hosting actively growing black holes. These black holes, known as quasars, have masses close to a billion times that of the Sun, while their host galaxies are almost one hundred times larger. This mass ratio is similar to what is found in the more recent universe, providing valuable insights into the early stages of the universe’s evolution.
In order to study the relation between host galaxies and black holes in the early universe, an international team of researchers, led by the Kavli Institute for the Physics and Mathematics of the Universe, utilized the James Webb Space Telescope. This powerful telescope, launched in December 2021, allows scientists to observe the formation of black holes and their connection to galaxies.
The detection of the host galaxies of quasars has always been a challenge for researchers due to the stark difference in brightness between the two. However, the superb sensitivity and ultra-sharp images provided by the James Webb Space Telescope at infrared wavelengths have finally enabled scientists to study this phenomenon in the early universe.
The team observed two quasars, named HSC J2236+0032 and HSC J2255+0251, when the universe was approximately 860 million years old. The detection of these quasars’ host galaxies represents the earliest epoch to date at which starlight has been observed in a quasar, providing valuable data for further analysis.
The images of the two quasars were taken using the JWST’s NIRCam instrument, which operates at infrared wavelengths. Through careful modeling and subtraction of the glare from the accreting black holes, the host galaxies became apparent. The detection of the host galaxy was further supported by the stellar signature observed in a spectrum taken by the JWST’s NIRSPEC for J2236+0032.
Analysis of the host galaxy photometry revealed that these quasar host galaxies are massive, measuring 130 and 34 billion times the mass of the Sun, respectively. The speed of the turbulent gas near the quasars suggests that the black holes powering them are also massive, measuring 1.4 and 0.2 billion times the mass of the Sun. This ratio of black hole mass to host galaxy mass is similar to that found in galaxies in the more recent past, indicating that the relationship between black holes and their hosts was already established just 860 million years after the Big Bang.
The research team, led by Xuheng Ding, John Silverman, and Masafusa Onoue, plans to continue studying this phenomenon with a larger sample using the James Webb Space Telescope. This will further enhance our understanding of the coevolution of black holes and their host galaxies. The team has also been granted additional time in the next cycle of JWST operations to study the host galaxy of J2236+0032 in greater detail.
The discovery of these ancient galaxies with massive black holes raises important questions for astrophysicists. How did these black holes grow to such enormous sizes when the universe was so young? Additionally, the clear relation observed between the mass of supermassive black holes and the much larger galaxies in which they reside poses a “chicken-or-egg” problem on a cosmic scale. Further research and observations with the James Webb Space Telescope will provide valuable insights into these puzzling questions about the early universe.
Reference: “Detection of stellar light from quasar host galaxies at redshifts above 6” by Xuheng Ding, Masafusa Onoue, John D. Silverman, et al., published in the journal Nature. DOI: 10.1038/s41586-023-06345-5