Astrophysics (Index)About

supermassive black hole

(black hole with a mass of millions to billions of solar masses)

A supermassive black hole (SMBH) is a very large black hole, generally in the center of a galaxy. A black hole is considered "supermassive" if its mass is on the order of millions (or hundreds of thousands) of solar masses or more, sometimes cited as 108 through 109 as typical (as opposed to a stellar-mass black hole, likely to be about 5 to 50 solar masses). The largest observed as of 12/2019 is on the order of 40 billion solar masses. A SMBH hole has been detected at the center of the Milky Way by observing the tight orbits of stars around it, and it is thought that galaxies larger than dwarf galaxies generally host them. Such large black holes are considered the energy source for active galactic nuclei (AGNs). Some methods of estimating the mass of SMBHs:

A supermassive black hole binary (SMBBH) is a pair of co-orbiting SMBHs. They are thought to result from galaxy mergers.

There is a mystery regarding SMBH formation since the Eddington luminosity would seem to regulate their growth. Current SMBHs have had enough time to grow, but quasars at extreme redshifts suggest a power source that only an SMBH can provide, which would have had insufficient time to grow, and furthermore, there have not been observations suggesting some kind of atypical rapid growth in process.

Regarding terms, SBH is occasionally used to mean SMBH, but perhaps more often to mean "stellar black hole". SMBH unfortunately might be used or read to mean "stellar mass" or "solar mass", but its use as "supermassive" appears pretty consistent.

(black hole type,galaxies,object type)
Further reading:

Referenced by pages:
accretion disk
accretion rate
active galaxy
active galactic nucleus (AGN)
AGN corona
broad emission line region
black hole accretion rate (BHAR)
black hole binary (BHB)
BlackHoleCam (BHC)
black hole mass function (BHMF)
black hole shadow
black hole (BH)
broad-line region (BLR)
binary SMBH (BSMBH)
dark matter
direct collapse black hole (DCBH)
Event Horizon Telescope (EHT)
extreme mass ratio inspiral (EMRI)
exotic star
final parsec problem
galactic bulge
galactic center
gravitational potential energy
gravitational wave spectrum
hypercompact stellar system (HCSS)
IRAS 13224-3809
Kelvin-Helmholtz mechanism
Lyman-alpha forest
Sombrero Galaxy (M104)
Messier 106 (M106)
Messier 84 (M84)
Meier paradox
M-sigma relation
solar mass (MSun)
NGC 1600
Centaurus A
nanohertz gravitational waves
pulsar timing array (PTA)
retrograde accretion
radio galaxy (RG)
Radio Galaxy Zoo (RGZ)
Romulus simulations
Sag A*
Schwarzschild radius (RS)
SGR J1745-2900
SMBH formation
Soltan argument
tidal disruption event (TDE)
3C 348
X-ray source