Astronomers have caught an intermediate black hole devouring a star in a cluster associated with a lenticular galaxy, located nearly 800 million light-years away. The event made it possible to measure its mass and spin, and will help test different hypotheses about dark matter.

An investigation carried out at the University of Arizona, in the United States, managed to measure key parameters of an intermediate black hole, while it was feeding on a star: by specifying its mass and its rotation, scientists will be able to advance in aspects such as the formation of holes supermassive blacks in the center of galaxies or the properties of dark matter, among others.

The moment a black hole devours a star, it produces what astronomers call a “tidal disruption event.” The removal of the star is accompanied by a burst of radiation, with an impact capable of dwarfing the combined light of all the stars that are part of the host galaxy of the black hole, in a phenomenon that can extend for months and even years.

Specifically, when a star gets too close to a black hole, gravitational forces generate intense tides, driving currents of gas that “trap” the star and lead to a cataclysmic phenomenon. In these tidal disruption events huge amounts of energy are released, overshadowing and darkening the galaxy in some cases.

The importance of intermediate black holes
Using X-rays, American astronomers analyzed a tidal disruption event known as J2150 to make the first measurements of the mass and spin of the black hole that starred in the event. This black hole is of a particular type: an intermediate mass black hole. They are especially difficult to discover, but they hide important data about the formation of the universe.

Intermediate black holes have a mass in the range of 100 to 1 million solar masses. They are significantly more massive than stellar black holes, but less than supermassive black holes. In the example studied, it could be confirmed that the protagonist was an intermediate black hole, in an extraordinary opportunity to observe hidden and still unexplained phenomena.

According to a press release, getting a better handle on how many authentic intermediate black holes exist can help determine which theories of supermassive black hole formation are correct. For example, one of them maintains that supermassive black holes that are located in the heart of galaxies are formed from the integration of several intermediate black holes.

Mass and twist In the framework of the new research, published in The Astrophysical Journal, the scientists determined that the intermediate black hole in question has a mass of approximately 10,000 solar masses. Supermassive black holes, meanwhile, have between 1 million and 10 billion times the mass of our Sun. On the other hand, measuring the spin of the black hole will allow researchers to test hypotheses about the nature of dark matter, which is believed to make up most of the matter in the universe. Dark matter can consist of unknown elementary particles that have not yet been seen in laboratory experiments. Among the candidates are hypothetical particles known as ultralight bosons, for example.

Reference
Mass, Spin, and Ultralight Boson Constraints from the Intermediate-mass Black Hole in the Tidal Disruption Event 3XMM J215022.4–0551. Sixiang Wen, Peter G. Jonker, Nicholas C. Stone, and Ann I. Zabludoff. The Astrophysical Journal (2021) .DOI: https: //doi.org/10.3847/1538-4357/ac00b5