Messier galaxies with precisely known black holes are all included. Despite this, the majority of well-known black holes above 1 billion M ☉ are shown. In addition, there are several hundred citations for black hole measurements not yet included on this list.
Note that this list is very far from complete, as the Sloan Digital Sky Survey (SDSS) alone detected 200 000 quasars, which likely may be the homes of billion-solar-mass black holes. using the BLRM method, and the other from Charles Nelson using λ5007 value and velocity dispersion. Some objects in this list have two citations, like 3C 273 one from Bradley M. This list contains supermassive black holes with known masses, determined at least to the order of magnitude. Most of the time, the masses derived from the given methods contradict each other's values. Such methods, such as broad emission-line reverberation mapping (BLRM), Doppler measurements, velocity dispersion, and the aforementioned M–sigma relation have not yet been well established. SMBHs with accurate masses are limited only to galaxies within the Laniakea Supercluster and to active galactic nuclei.Īnother problem for this list is the method used in determining the mass. There is extreme difficulty in determining the mass of a particular SMBH, and so they still remain in the field of open research. Īlthough SMBHs are currently theorized to exist in almost all massive galaxies, more massive black holes are rare with only fewer than several dozen having been discovered to date. This correlation, although based on just a handful of galaxies, suggests to many astronomers a strong connection between the formation of the black hole and the galaxy itself. The reason for this assumption is the M–sigma relation, a tight (low scatter) relation between the mass of the hole in the ~10 galaxies with secure detections, and the velocity dispersion of the stars in the bulges of those galaxies. Nevertheless, it is commonly accepted that the center of nearly every galaxy contains a supermassive black hole. In all other galaxies observed to date, the rms velocities are flat, or even falling, toward the center, making it impossible to state with certainty that a supermassive black hole is present. In these galaxies, the mean square (or root mean square) velocities of the stars or gas rises as ~1/r near the center, indicating a central point mass. Unambiguous dynamical evidence for SMBHs exists only in a handful of galaxies these include the Milky Way, the Local Group galaxies M31 and M32, and a few galaxies beyond the Local Group, e.g. In some galaxies, there are even binary systems of supermassive black holes, see the OJ 287 system.
Comparisons of large and small black holes in galaxy OJ 287 to the Solar System.Ī supermassive black hole (SMBH) is an extremely large black hole, on the order of hundreds of thousands to billions of solar masses ( M ☉), and is theorized to exist in the center of almost all massive galaxies.
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