The largest type of black holes — called supermassive black holes — have masses of the order of hundreds of thousands to billions of times the mass of the Sun. The mass of our Sun is 1.989 x 1030 kilograms, approximately 333,000 times more massive than the Earth.
It is theorized that nearly all large galaxies contain a supermassive black hole, located at the center of the galaxy. In fact, there is a strong connection between the formation of the black hole and the galaxy itself.
Although there are millions of supermassive black holes in the universe, the incredibly massive ones are rare, and only fewer of them have been identified to date.
It Is Extremely Difficult To Determine The Mass Of A Large Black Hole
To measure the mass of supermassive black holes, scientists use various complex techniques, including Doppler measurements, broad emission-line reverberation mapping, M-sigma relation, and velocity dispersion.
Masses derived from these methods often contradict each other’s outcomes. Therefore, they have still remained in the area of open research.
Below, we have gathered some of the biggest black holes with known masses, measured at least to the order of magnitude. The list is far from complete, but it gives a rough idea of how complex and vast our universe is.
8. Central black hole of Phoenix Cluster
Powerful radio jets from the supermassive black hole at the center of a galaxy in the Phoenix Cluster | The cavities within the blue region is imaged by NASA’s Chandra X-ray observatory.
Solar Mass: 2×1010
Phoenix Cluster is one of the most massive cluster known, with a large portion of its mass in the form of dark matter and its intracluster medium.
A supermassive black hole in the central galaxy of clusters pumps energy into the system. It is believed to be 20 billion times more massive than the Sun, and its event horizon should be in the order of 118 billion kilometers in diameters.
Chandra data and various observations at the other wavelengths have shown that this black hole is growing rapidly, at the rate of 60 times the mass of Sun every year. But since it is already very large, this rate is not sustainable. The growth cannot last more than 100 million years.
7. NGC 4889
The brightest orb near the center is NGC 4889 galaxy, containing a cosmic surprise | Credit: NASA
Solar Mass: 2.1×1010
Discovered in 1785, NGC 4889 is the brightest galaxy within the northern Coma Cluster, located at a median distance of 308 million light-years from Earth.
At the heart of the NGC 4889 sits one of the biggest black holes that heats the intracluster medium through the friction generated from infalling dust and gases. This supermassive black hole is nearly 5,200 times more massive than the Milky Way’s central black hole, weighing about 21 billion solar masses.
The event horizon of the black hole is somewhere between 20 and 124 billion kilometers wide, or equivalent to 2 to 12 times the diameter of Pluto’s orbit.
It is currently slumbering and stars forming around it seem to remain stable. However, Hubble Space Telescope has found an ionized medium around the supermassive black hole, suggesting that NGC 4889 may have been a quasar billions of years ago.
Quasar is an extremely bright active galactic nucleus, in which a supermassive black hole is surrounded by a gaseous accretion disk. It pulls in dust and gas so powerfully that it heats the matter to millions of degrees, resulting in massive releases of energy.
6. APM 08279+5255
Solar Mass: 2.3×1010
In 2002, Chandra observations revealed evidence of high-speed winds blowing gases away (as high as 40% of the speed of light) from the supermassive black hole that power the quasar APM 08279+5255.
The quasar is located in the Lynx constellation and has a luminosity of one quadrillion times the luminosity of the Sun. It is a bright source at almost all wavelengths and has become one of the most investigated distant objects.
The supermassive black hole powering the APM 08279+5255 weighs 23 billion solar masses (measured via molecular disk velocities). However, another measurement technique called reverberation mapping shows the black hole weighs 10 billion solar masses – a huge difference between both measurement techniques.
The double image of the quasar is caused by gravitational lensing (bending of its light by an intervening galaxy). This effect also intensifies the quasar light by 100 times, enabling an in-depth study of its characteristics even though it is 12 billion light-years away.
In the recent decade, researchers have also discovered that APM 08279+5255 has enough water to fill Earth’s oceans more than 100 trillion times.
5. NGC 6166
Close-up view of NGC 6166 galaxy by Hubble Space Telescope
Solar Mass: 3×1010
NGC 6166 is one of the most luminous elliptical galaxies [in terms of X-ray emissions] located 490 million light-years away in the Hercules constellation. About 39,000 globular clusters orbit the galaxy, indicating that the halo of NGC 6166 blends smoothly with the intra-cluster medium.
There is a supermassive black hole in the center of the galaxy which has a mass 30 billion times that of the Sun. It engulfs nearly 200 solar masses of gas every year, producing large relativistic jets.
Scientists have theorized that the center of the galaxy may also harbor several O-type stars; rare, blue-white stars with temperatures more than 30,000 kelvins.
H1821+643 | Credit: WIYN Observatory, NASA
Solar Mass: 3×1010
The highly luminous quasar, H1821+643, is located in a giant, strong cooling flow cluster, within the constellation of Draco.
In 2014, researchers detected H1821+643 as one of the most massive black holes and accurately calculated its mass, which is equivalent to 30 billion solar masses. The event horizon of the black hole is 1,150 AU wide (1 Astronomical Unit is equal to about 150 million kilometers), and its average density is 22 gram per meter cube, less than air on Earth.
Researchers also found that the intracluster medium around the quasar is substantially different than other large galaxy clusters – the entropy and temperature are significantly lower, and have much steeper gradients.
Recently, a detailed analysis of the quasar proved that our universe is filled with massive amounts of ionized hydrogen, accompanied by ionized oxygen.
3. IC 1101
IC 1101 galaxy observed in June 1995 with Hubble Space Telescope
Solar Mass: (4-10)×1010
One of the largest and brightest galaxies in the universe, IC 1101 hosts a supermassive black hole at its center, with a mass ranging from 40 to 100 billion times the mass of the Sun.
It’s an elliptical galaxy located 1.04 billion light-years from Earth. The galaxy has a mass of about 100 trillion stars and extends 2 million light-years from its core.
Like other massive galaxies, IC 1101 contains a large number of metal-rich stars, a few of which are 11 billion years old and appear golden yellow in color.
2. S5 0014+81
Artistic impression of a very bright quasar similar to S5 0014+81 enclosed by a gaseous accretion disk with two energetic jets
Solar Mass: 4×1010
S5 0014+81 belongs to the most energetic type of active galactic nuclei – it is a blazar located near the high declination region of the constellation Cepheus, about 12.07 billion light-years from Earth.
It is the 6th brightest quasar known so far, with over 1041 watts of luminosity. To put this into perspective, it is 25,000 times brighter than all stars in the Milky Way galaxy combined.
The central black hole of the blazar is extremely violent – it engulfs an enormous amount of materials (over 4,000 solar masses of matter) every year.
In 2009, data obtained from Neil Gehrels Swift Observatory allowed scientists to calculate the mass of the central black hole. They found it to be 40 billion times more massive than our Sun, and its event horizon is 236.7 billion kilometers wide, or equivalent to 40 times the radius of Pluto’s orbit.
1. TON 618
Solar Mass: 6.6×1010
TON 618 is a hyperluminous quasar located 10.37 billion light-years from Earth. It contains the biggest black hole [known to mankind], weighing 66 billion times the mass of our Sun.
It was first discovered in 1957 while surveying faint blue stars that do not lie on the Milky Way plane. A more detailed radio survey conducted in 1970 identified TON 618 as a quasar.
TON 618 is considered an accretion disc of extremely hot gas swirling around the massive black hole in the galaxy’s center. It is so bright, it outshines the rest of the galaxy. In fact, it is one of the brightest objects in the Universe with a luminosity of 4×1040 watts, which is equivalent to 140,000 billion times the Sun’s.
Since the gas in the accretion disc is traveling at very high speeds (nearly 7,000 km/s), the black hole is exerting an exceptionally strong gravitational force. And the event horizon of such a massive black hole would be 2,600 AU in diameters.