# Tag Info

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The Brightest Cluster Galaxy (BCG) in Abell 2261 ("Abell 2261-BCG") is a massive elliptical; these almost always seem to have supermassive black holes in their centers. In addition, the center of the galaxy has a large region of relatively low stellar density (a "core"), something usually thought to be produced by the merger of two SMBHs ...

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The observation did indeed confirm general relativity, see e.g. Lisa Grossman wrote in October 2020 for ScienceNews: The first black hole image helped test general relativity in a new way That iconic image, of the supermassive black hole at the center of the galaxy M87 about 55 million light-years away, showed that the shadow closely matched general ...

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I am sorry to say, but the best resources are still books. If it is really a no-go, read further. It is very likely, that you can find and buy astronomy books on Arabic on the Internet. First start with popular science books. Buy multiple books. To learn something, books are still somehow far better than the Internet. Check the Arabic wikipedia, like this ...

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We can think of the magnetic field lines as part of its host gas in the jet, in the sense that when the gas moves, the magnetic lines of force must move with it - and vice versa. Magnetic field lines passing through an accretion disc are thus forced to rotate with the disc. The particles of ionised gas above and below the disc are then urged to rotate with ...

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Physics doesn't require a black hole at the centre of a galaxy, it just indicates that it is likely. All you need is mass. If the mass is not dense enough to form a black hole, it can still be high enough for a galaxy to grow. (Also, finding nothing is not the same as nothing being there. So nobody is ruling out the existence of a black hole there)

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Þe olde goode dimensional analysis can help. The Hawking radiation is essentially a quantum field effect of the same nature as the Unruh effect. Quantum fields “live” in a distorted space-time of the hole and do not need to know anything about gravitation. Like for the Unruh effect (having $c/a$ as its characteristic time), there is a natural time scale for ...

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