Radio signals unveil secrets of massive galaxies

Black holes—the cosmic behemoths known for powering some of the brightest radio wave sources in the universe—were the focal point of a study led by Associate Professor Michael Brown, from the School of Physics and Astronomy ...

A 10-billion-year, 50,000-light-year journey to a black hole

A star near the supermassive black hole at the center of the Milky Way galaxy originated outside the galaxy according to a new study published in Proceedings of the Japan Academy, Series B. This is the first time a star of ...

Unveiling black hole spins using polarized radio glasses

A cornerstone but surprising prediction arising from Einstein's theory of general relativity is the existence of black holes, which astronomers later found to be widespread throughout the universe. Key characteristics of ...

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Black hole

In general relativity, a black hole is a region of space in which the gravitational field is so powerful that nothing, including light, can escape its pull. The black hole has a one-way surface, called an event horizon, into which objects can fall, but out of which nothing can come. It is called "black" because it absorbs all the light that hits it, reflecting nothing, just like a perfect blackbody in thermodynamics. Quantum analysis of black holes shows them to possess a temperature and Hawking radiation.

Despite its invisible interior, a black hole can reveal its presence through interaction with other matter. A black hole can be inferred by tracking the movement of a group of stars that orbit a region in space which looks empty. Alternatively, one can see gas falling into a relatively small black hole, from a companion star. This gas spirals inward, heating up to very high temperature and emitting large amounts of radiation that can be detected from earthbound and earth-orbiting telescopes. Such observations have resulted in the scientific consensus that, barring a breakdown in our understanding of nature, black holes do exist in our universe.

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