Scientists record how a black hole devours a star

According to researchers at the University of Arizona in the US, something that young children and black holes have in common is that they both eat in a disorderly way, leaving ample evidence of food trails.

But while one may leave behind pasta or yogurt splatters, the other creates a sequel of mind-boggling proportions. When a black hole devours a star, the star’s destruction is accompanied by a burst of radiation that can outshine the combined light from each star in the black hole’s host galaxy for months and even years.

In an article published in The Astrophysical Journal, a team of astronomers led by Sixiang Wen, a postdoctoral research associate at the University of Arizona Steward Observatory, used the X-rays emitted by a known tidal disruption event to perform the first measurements of both the mass and the rotation of the black hole.

It is hole it is of a particular type, of intermediate mass, which has eluded observation for a long time.

“The fact that we were able to catch this black hole while it was devouring a star offers an extraordinary opportunity to observe what would otherwise be invisible.” said Ann Zabludoff, a professor of astronomy at the University of Arizona and a co-author of the paper. “By analyzing the flare, we were able to better understand this elusive category of black holes, which may well represent the majority of those found at the centers of galaxies.”

According to information released by the university, dozens of tidal disruption events have been seen in the centers of large galaxies that host supermassive black holes, and some have also been observed in the centers of small galaxies that could contain holes. intermediate blacks. However, previous data had never been detailed enough to show that a single tidal disruption eruption was driven by an intermediate black hole.

Thanks to modern astronomical observations, we know that the centers of almost all galaxies that are similar to or larger in size than our Milky Way , said study co-author Nicholas Stone, a senior lecturer at the Hebrew University of Jerusalem. “These giants vary in size between 1 million and 10 billion times the mass of our Sun, and they become powerful sources of electromagnetic radiation when too much interstellar gas falls in their vicinity.”

The mass of these black holes is closely correlated with the total mass of their host galaxies; the largest are home to the largest supermassive black holes.

“We still know very little about the existence of black holes in the centers of galaxies smaller than the Milky Way”, said co-author Peter Jonker of Radboud University and the SRON Space Research Institute, both in the Netherlands. “Due to the limitations of observation, it is challenging to discover central black holes much smaller than

Despite their presumed abundance, the origins of supermassive black holes remain unknown, and many different theories are currently competing to explain them, according to Jonker. Intermediate mass black holes could be the seeds from which they grow.

“So if we get a better handle on how many authentic intermediate black holes there are, this can help determine which theories of supermassive black hole formation are correct.” said.

Its relationship with dark matter

Even more exciting, according to Zabludoff, is the measurement of the spin of J2150 that the group was able to obtain that has clues to how black holes grow and possibly to particle physics.

This black hole has a fast spin, but not the fastest possible spin, Zabludoff explained, raising the question of how the black hole ends up with a spin in this range.

“It is possible that the black hole has formed that way and has not changed much since then, or that two black holes of intermediate mass recently merged to form this one”, said. “We know that the spin that we measure excludes scenarios in which the black hole grows for a long time by constantly consuming gas or by many fast gas bubbles coming from random directions.”

Additionally, gyro measurement allows astrophysicists to test hypotheses about the nature of the spin. dark matter, which is believed to make up most of the matter in the universe and may consist of unknown elementary particles that have not yet been seen in laboratory experiments. Among the candidates are hypothetical particles known as ultralight bosons, Stone explained.

“If these particles exist and have masses in a certain range, they will prevent an intermediate mass black hole from spinning rapidly”, said. “However, the one on the J2150 spins fast. Therefore, our measurement rules out a wide class of ultralight boson theories, showing the value of black holes as extraterrestrial laboratories for particle physics. “

El Tiempo, Colombia / GDA

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