Supermassive black hole - Wikipedia.pdf - 1/24/2020...

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1/24/2020Supermassive black hole - Wikipedia1/16Supermassive black holeAsupermassiveblackhole(SMBHorsometimesSBH) is the largest type ofblack hole,containing a mass of the order of hundreds ofthousands to billions of times the mass of the Sun(M). Black holes are a class ofastronomicalobject that have undergonegravitational collapse,leaving behindspheroidal regions of space fromwhichnothingcanescape,notevenlight.Observational evidence indicates that nearly alllargegalaxies contain a supermassive black hole,located at thegalaxy's center.[3][4]In the case oftheMilky Way, the supermassive black holecorresponds to the location ofSagittarius A* attheGalactic Core.[5][6]Accretion ofinterstellargas onto supermassive black holes is the processresponsible for poweringquasars and other typesofactive galactic nuclei.DescriptionHistory of researchFormationActivity and galactic evolutionEvidenceDoppler measurementsIn the Milky WayOutside the Milky WayHawking radiationSee alsoReferencesFurther readingExternal linksSupermassive black holes have properties that distinguish them from lower-mass classifications.First, the averagedensity of a SMBH (defined as the mass of the black hole divided by the volumewithin itsSchwarzschild radius) can be less than the density ofwater in the case of some SMBHs.[7]This is the first direct image taken of a supermassiveblack hole, located at the galactic core of Messier87.[1][2]It shows a heated accretion ring orbiting theobject at a mean separation of 350 AU, or ten timeslarger than the orbit of Neptune around the Sun. Thedark center is the event horizon and its shadow.ContentsDescription
1/24/2020Supermassive black hole - Wikipedia2/16This is because the Schwarzschild radius is directlyproportional to itsmass. Since the volume of aspherical object (such as theevent horizon of a non-rotating black hole) is directly proportional to thecube of the radius, the density of a black hole is inversely proportional to the square of the mass, andthus higher mass black holes have loweraverage density.[8]In addition, thetidal forces in the vicinityof theevent horizon are significantly weaker for supermassive black holes. The tidal force on a body atthe event horizon is likewise inversely proportional to the square of the mass:[9]a person on thesurface of the Earth and one at the event horizon of a 10 millionMblack hole experience about thesame tidal force between their head and feet. Unlike withstellar mass black holes, one would notexperiencesignificant tidal force until very deep into the black hole.[10]Some astronomers have begun labeling black holes of at least 10billionMasultramassive blackholes.

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Mingela A
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Black hole, supermassive black hole

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