An as yet undiscovered black hole announced its existence to astronomers when it broke apart and devoured a star that was wandering near it.
A medium-mass black hole is located in a dwarf galaxy a million light-years away a land The star tore apart in an event astronomers call a tidal disturbance event (TDE). TDE made itself visible when it released a wave of radiation so powerful that it briefly outperformed every star in its dwarf galaxy’s house combined.
TDE can help scientists understand the relationship between galaxies and black holes inside them. It also provides astronomers with another intermediate black hole to study. “This discovery has caused widespread excitement because we can use tidal perturbation events to not only find more intermediate-mass black holes in a quiet dwarf.” galaxies but also to measure their masses,” research co-author and University of California, Santa Cruz (UCSC) astronomer Ryan Foley said in statement (Opens in a new tab).
TDE glow – rhombus in 2020neh (Opens in a new tab)It was first observed by astronomers using the Young Supernova Experiment (YSE), an astronomical survey that detects short-lived cosmic events such as supernova explosions, in which a black hole first began devouring a star.
Observing this initial moment of destruction was vital in allowing an international team led by UCSF scientists, first research author and Niels Bohr Institute astronomer Charlotte Angus to measure and find the mass of the black hole around it. 100,000 million times the mass of the Sun. (Opens in a new tab)
TDEs have been used successfully to measure the mass of supermassive black holes in the past, but this is the first time they have been shown to work in documenting the masses of smaller intermediate-mass black holes.
This means that the initial observation of the incredibly fast AT 2020neh glow could provide a baseline for measuring the masses of medium-sized black holes in the future.
“The fact that we were able to capture this medium-sized black hole while it was devouring a star, gave us a wonderful opportunity to discover what might have been hidden from us,” said Angus. Moreover, we can use the properties of the glow itself to understand this elusive group of medium-weight black holes, which can represent the majority of black holes at the centers of galaxies.
This medium-sized class of black holes has a mass range between 100 and 100,000 times the sunmaking them much more massive than stellar-mass black holes but much smaller than the supermassive black holes at the core of most galaxies, including Milky Way.
Physicists have long suspected that supermassive black holes, whose masses can be millions or even billions of times the mass of the Sun, can grow to such massive masses as a result of merging medium-mass black holes.
One theory regarding the mechanism that could facilitate this growth is that the early universe was rich in dwarf galaxies with intermediate black holes.
When these dwarf galaxies merged or were swallowed up by larger galaxies, the intermediate black holes within them scattered each other apart, thus growing mass. This sequential process of increasingly larger mergers will eventually lead to giant black hole Titans are at the heart of most galaxies today.
“If we can understand how many intermediate-mass black holes are out there – how many and where there are – we can help determine whether our theories about the formation of supermassive black holes are correct,” said co-author and professor of astronomy at UCLA. Enrico Ramirez Ruiz is an astrophysicist.
One of the remaining questions regarding black hole growth theory is: Do all dwarf galaxies have their own intermediate-mass black hole? This is difficult to answer because because black holes trap light behind an outer boundary called the event horizon, they are effectively invisible unless they feed on the surrounding gas and dust, or if they rupture stars in TDEs.
Astronomers can use other methods, such as looking at the gravitational effect of stars orbiting them, to infer the presence of black holes. However, these detection methods are currently not sensitive enough to be applied to distant black holes in the centers of dwarf galaxies.
As a result, a few medium-mass black holes have been tracked down to dwarf galaxies. This means that by detecting and measuring TDE flares for medium-sized black holes such as AT 2020neh, it could be a vital tool in settling the debate over the growth of supermassive black holes.
The team’s research was published November 10 in the journal natural astronomy (Opens in a new tab).
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