2023-09-20 06:00:09
These are celestial objects so massive that they exceed a million times the mass of the Sun and are at the heart of every galaxy, including ours: supermassive black holes. A new study has just lifted a corner of the veil concerning their origin and their role in the evolution of the Universe (The Universe is the set of everything that exists and the laws that govern it.).
A supermassive black hole (the small black dot in the center) absorbs surrounding matter, forming (In intonation, changes in fundamental frequency are perceived as variations of…) a spiral (In mathematics, a spiral is a curve that begins at a central point and then branches out…). Part of the energy (In the common sense energy designates anything that allows work to be carried out, to produce…) generated by the swirling matter is converted into radiation (Radiation, synonymous with radiation in physics , designates the process of emission or…). Supermassive black holes with such bright outlines are called “quasars”.
Credit: Yoshiki Matsuoka, Ehime University
Supermassive black holes are closely linked to the formation of galaxies. Their mass is almost always a thousandth of that of the host galaxy, suggesting coevolution (In biology, the term, introduced in 1964, coevolution designates the transformations which…). Understanding the origin of supermassive black holes is therefore essential to also elucidate the processes of galaxy formation.
The study focused on the early Universe, less than a billion years following the Big Bang (The Big Bang is the dense and hot era that the universe experienced…) . The researchers used the Subaru telescope in Hawaii to observe a special class of supermassive black holes called “quasars”, emitting from nearby. neighborhood corresponds to an axiomatic approach equivalent to that of the…) of their horizon (Conceptually, the horizon is the limit of what can be observed, due to its own…) of powerful jet events luminous.
The team observed an area of the sky equivalent to 5,000 times the full moon and discovered 162 quasars in the early Universe. Of these, 22 lived in a period when the Universe was less than 800 million years old, the oldest period ever identified for quasars.
The study also examined the “luminosity function,” a measure that describes the spatial density of quasars as a function of the radiated energy. The results show that quasars formed very quickly in the early Universe.
At the same time, the Universe experienced a phase of “cosmic reionization”. Quasars have been considered as a possible energy source for this reionization. However, the study reveals that their contribution was minimal, suggesting that other energy sources were needed.
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