Researchers have observed and analyzed X-ray emissions from the most luminous quasar known in the last 9 billion years of cosmic history, called SMSS J114447.77-430859.3, or J1144 for short. Analysis of such X-ray emissions provides insightful new insights into the inner workings of quasars and how they interact with their environment.
Housed in a galaxy 9.6 billion light-years from Earth, J1144 is extremely powerful, shining 100 trillion (million million) times brighter than the Sun. J1144 is much closer to Earth than other sources of the same luminosity , allowing astronomers to better understand the black hole that powers the quasar and its surrounding environment.
Quasars are among the brightest and most distant objects in the known universe. Its colossal brightness is generated by the fall of gas into a supermassive black hole. They can be described as very high luminosity active galactic nuclei emitting large amounts of electromagnetic radiation observable at radio, infrared, visible, ultraviolet, and X-ray wavelengths. J1144 was initially observed at visible wavelengths in 2022 by SMSS (Sky Mapper Southern Survey).
For the new study, the team of Elias Kammoun, from the Toulouse Institute for Research in Astrophysics and Planetology in France, and Zsofi Igo, from the Max Planck Institute for Extraterrestrial Physics in Germany, combined observations from several space-based observatories: the onboard eROSITA instrument the SRG (Spectrum-Roentgen-Gamma) space observatory, the XMM-Newton, the NuSTAR (Nuclear Spectroscopic Telescope Array) and the Neil Gehrels Swift.
Artist’s impression of a quasar. (Illustration: NOIRLab / NSF / AURA / J. da Silva. CC BY)
The study authors used data from the four observatories to measure temperature. Analysis of the data on the X-rays emitted by the quasar indicated a temperature of approximately 350 million degrees Celsius, more than 60,000 times the temperature at the surface of the Sun. The team also discovered that the mass of the black hole at the center of the quasar is about 10,000 million times greater than the mass of the Sun, and that the rate at which the black hole grows is of the order of 100 solar masses per year, that is, the equivalent of swallowing 100 stars like the Sun each year.
The observations have clarified some things but also raise intriguing new questions… The X-ray light from the quasar varied on a time scale of a few days, which is not usually observed in quasars with black holes as large as the one residing in J1144. The typical time scale of variability for a black hole of this size would be on the order of months or even years. The observations also showed that while a part of the gas is swallowed by the black hole, another part is expelled in the form of extremely powerful winds, injecting large amounts of energy into the galaxy where the hole resides.
The study is titled “The first X-ray look at SMSS J114447.77-430859.3: the most luminous quasar in the last 9 Gyr”. And it has been published in the academic journal Monthly Notices of the Royal Astronomical Society. (Source: N.CYT by Amazings)
