Reviewed by Lexie CornerNov 21 2024
A study published in Astronomy & Astrophysics by INAF researchers examines 21 distant quasars and discovers that these objects are undergoing rapid accretion.
Artist’s impression of an accreting supermassive black hole, surrounded by gas spiraling toward it along the equatorial plane (the accretion disk) and emitting powerful winds of matter as it falls in. Image Credit: Emanuela Tortosa
New evidence has been uncovered that explains how supermassive black holes formed in the first billion years of the universe’s existence.
This provides valuable insights into their formation and evolution, as well as that of their host galaxies.
The study presents new data showing how supermassive black holes, with masses several billion times that of the Sun, developed rapidly in less than a billion years after the Big Bang. Led by experts from the National Institute for Astrophysics (INAF), the study examines a sample of 21 quasars, some of the most distant known, detected in the X-ray spectrum by the XMM-Newton and Chandra space telescopes.
The findings suggest that the supermassive black holes at the centers of these quasars, among the first to form during the cosmic dawn, may have reached their extraordinary masses through extremely fast and intense accretion.
Central supermassive black holes, also known as active galactic nuclei, are the driving force behind quasars—active galaxies that release vast amounts of energy as they consume matter. These objects are located far from us and are exceptionally bright. The quasars studied in this research are among the most distant objects ever observed, existing before the universe was one billion years old.
This study analyzed X-ray emissions from these objects, revealing an unexpected behavior of the supermassive black holes at their centers. A connection was found between the shape of the X-ray emission and the speed of the quasars' matter winds. This relationship links the wind speed, which can reach millions of kilometers per second, to the temperature of the gas in the corona, the region emitting X-rays closest to the black hole.
The findings show that the corona is closely related to the black hole's powerful accretion mechanisms. Quasars with low-energy X-ray emission, and therefore a lower temperature in the corona, produce faster winds. This suggests a highly rapid growth phase that exceeds a physical limit for matter accretion, known as the Eddington limit, hence the term "super-Eddington." In contrast, quasars with higher-energy X-ray emissions are likely to have slower winds.
Our work suggests that the supermassive black holes at the center of the first quasars formed within the first billion years of the Universe's life may have actually increased their mass very rapidly, challenging the limits of physics. The discovery of this connection between X-ray emission and winds is crucial for understanding how such large black holes could have formed in such a short time, thus providing a concrete clue to solve one of the greatest mysteries of modern astrophysics.
Alessia Tortosa, Study Lead Author and Researcher, INAF
The results were mostly obtained through the analysis of data gathered with the European Space Agency’s (ESA) XMM-Newton space telescope, which allowed for nearly 700 hours of quasar observations. The majority of the data, obtained between 2021 and 2023 as part of the Multi-Year XMM-Newton Heritage Program under the guidance of Luca Zappacosta, a researcher at INAF in Rome, is part of the HYPERION project, which intends to examine hyperluminous quasars during the cosmic start of the Universe.
A team of Italian scientists spearheaded the lengthy observation mission, which obtained critical funding from INAF and allowed for cutting-edge study of the evolutionary processes of the Universe’s early structures.
In the HYPERION program, we focused on two key factors: on one hand, the careful selection of quasars to observe, choosing the titans, meaning those that had accumulated as much mass as possible, and on the other hand, the in-depth study of their properties in X-rays, something never attempted before on such a large number of objects from the cosmic dawn. We hit the jackpot! The results we are getting are genuinely unexpected, and they all point to a super-Eddington growth mechanism of the black holes.
Luca Zappacosta, Researcher, INAF
The study provides valuable information for future X-ray missions such as ATHENA (ESA), AXIS, and Lynx (NASA), which are set to launch between 2030 and 2040. The findings will also be valuable for improving next-generation observational tools and developing better methodologies for studying black holes and active galactic nuclei in X-rays at distant cosmic epochs. These are critical components for understanding the genesis of the first galactic formations in the early Universe.
Journal Reference:
Tortosa, A. et. al. (2024) HYPERION. Shedding light on the first luminous quasars: A correlation between UV disc winds and X-ray continuum. Astronomy & Astrophysics. doi.org/10.1051/0004-6361/202449662