Examining images taken by NASA’s Hubble Space Telescope, astronomers discovered a black hole 21 billion times bigger than the sun — the biggest black hole known to humankind. The “supermassive” black hole is 300 million light years
away from us and resides right in the middle of the Coma Cluster, part
of the NGC 4889 galaxy, the Hubble Space Telescope’s official website explains. “The placid appearance of NGC 4889 can fool the unsuspecting observer,” reads the website.
A new form of diffuse galaxy has been discovered inside the Coma Cluster. This place is made 99.99% of dark matter, totally invisible as it doesn’t interact with light.
The galaxy is known as Dragonfly 44 and was discovered by astronomers Pieter van Dokkum and his colleagues.
The way star systems orbit around the center of a galaxy is inexplicable with “normal” physics. To account for the velocity variations and patterns we need to add a new ingredient to the gravitational pot: dark matter.
Dragonfly 44 in particular has so few stars that were the dark matter to be taken away, the galaxy would fly apart the same way you’d go flying if the cord holding the swing to a swing set were severed.
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA); Acknowledgment: K. Cook (LLNL) et al.
Explanation: Why are there faint rings around this spiral galaxy? Possibly because the galaxy, NGC 4911, is being pulled at by its neighbors as it falls into the enormous Coma Cluster of Galaxies. If NGC 4911 ends up like most of the galaxies in the central Coma cluster, it will become a yellowish elliptical galaxy, losing not only its outer layers, but dust, gas, and its cadre of surrounding satellite galaxies as well. Currently, however, this process is just beginning. Visible in the above deep image from the Hubble Space Telescope are NGC 4911’s bright nucleus, distorted spiral arms laced with dark dust, clusters of recently formed stars, unusual faint outer rings, dwarf companion galaxies, and even faint globular clusters of stars. Far in the distance many unassociated galaxies from the early universe are visible, some even through NGC 4911 itself. The Coma Cluster contains over 1,000 galaxies making it among the most massive objects known. NGC 4911 can be found to the lower left of the great cluster’s center.
Astronomers have uncovered a near-record breaking supermassive black hole, weighing 17 billion suns, in an unlikely place: in the center of a galaxy in a sparsely populated area of the universe. The observations, made by NASA’s Hubble Space Telescope and the Gemini Telescope in Hawaii, may indicate that these monster objects may be more common than once thought.
Until now, the biggest supermassive black holes – those roughly 10 billion times the mass of our sun – have been found at the cores of very large galaxies in regions of the universe packed with other large galaxies. In fact, the current record holder tips the scale at 21 billion suns and resides in the crowded Coma galaxy cluster that consists of over 1,000 galaxies.
The placid appearance of NGC 4889 can fool the unsuspecting observer. But the elliptical galaxy, pictured in this new image from the NASA/ESA Hubble Space Telescope, harbours a dark secret. At its heart lurks one of the most massive black holes ever discovered.
Located about 300 million light-years away in the Coma Cluster, the giant elliptical galaxy NGC 4889, the brightest and largest galaxy in this image, is home to a record-breaking supermassive black hole. Twenty-one billion times the mass of the Sun, this black hole has an event horizon – the surface at which even light cannot escape its gravitational grasp – with a diameter of approximately 130 billion kilometres. This is about 15 times the diameter of Neptune’s orbit from the Sun. By comparison, the supermassive black hole at the centre of our galaxy, the Milky Way, is believed to have a mass about four million times that of the Sun and an event horizon just one fifth the orbit of Mercury.
NGC 4911 is a spiral galaxy located deep within the Coma Cluster of galaxies, which lies 320 million light years away in the northern constellation Coma Berenices. The galaxy contains rich lanes of dust and gas near its centre. The existence of clouds of Hydrogen within the galaxy indicates ongoing star formation. This is rare for a spiral galaxy to be situated at the heart of a cluster. ~ Wikipedia
Credit: NASA/ESA/Hubble Heritage Team (STScI/AURA)
Record massive black holes discovered lurking in monster galaxies
An artist’s concept of stars moving in the central regions of a giant elliptical galaxy that harbors a supermassive black hole.
University of California, Berkeley, astronomers have discovered the largest black holes to date ‑- two monsters with masses equivalent to 10 billion suns that are threatening to consume anything, even light, within a region five times the size of our solar system.
These black holes are at the centers of two galaxies more than 300 million light years from Earth, and may be the dark remnants of some of the very bright galaxies, called quasars, that populated the early universe.
“In the early universe, there were lots of quasars or active galactic nuclei, and some were expected to be powered by black holes as big as 10 billion solar masses or more,” said Chung-Pei Ma, UC Berkeley professor of astronomy. “These two new supermassive black holes are similar in mass to young quasars, and may be the missing link between quasars and the supermassive black holes we see today.”
Black holes are dense concentrations of matter that produce such strong gravitational fields that even light cannot escape. While exploding stars, called supernovas, can leave behind black holes the mass of a single star like the sun, supermassive black holes have presumably grown from the merger of other black holes or by capturing huge numbers of stars and massive amounts of gas.
“These black holes may shed light on how black holes and their surrounding galaxies have nurtured each other since the early universe,” said UC Berkeley graduate student Nicholas McConnell, first author of a paper on the discovery published in the Dec. 8, 2011 issue of the British journal Nature by McConnell, Ma and their colleagues.
To date, approximately 63 supermassive black holes have been found sitting in the cores of nearby galaxies. The largest for more than three decades was a 6.3 billion solar mass black hole in the center of the nearby galaxy M87.
One of the newly discovered black holes is 9.7 billion solar masses and located in the elliptical galaxy NGC 3842, the brightest galaxy in the Leo cluster of galaxies, 320 million light years away in the direction of the constellation Leo. The second is as large or larger and sits in the elliptical galaxy NGC 4889, the brightest galaxy in the Coma cluster about 336 million light years from Earth in the direction of the constellation Coma Berenices.
According to McConnell, these black holes have an event horizon – the “abandon all hope” edge from which not even light can escape – that is 200 times the orbit of Earth, or five times the orbit of Pluto. Beyond the event horizon, each black hole has a gravitational influence that would extend over a sphere 4,000 light years across.
“For comparison, these black holes are 2,500 times as massive as the black hole at the center of the Milky Way Galaxy, whose event horizon is one fifth the orbit of Mercury,” McConnell said.
These 10 billion solar mass black holes have remained hidden until now, presumably because they are living in quiet retirement, Ma said. During their active quasar days some 10 billion years ago, they cleared out the neighborhood by swallowing vast quantities of gas and dust. The surviving gas became stars that have since orbited peacefully. According to Ma, these monster black holes, and their equally monster galaxies that likely contain a trillion stars, settled into obscurity at the center of galaxy clusters.
NGC 3842 (upper left) is the brightest galaxy in a rich cluster of galaxies. The black hole at its center (shown in middle as artist’s concept) is surrounded by stars distorted by its immense gravitational field. The black hole, which is seven times larger than Pluto’s orbit, would dwarf our solar system (inset).
Astronomers believe that many, if not all, galaxies have a massive black hole at the center, with the larger galaxies harboring larger black holes. The largest black holes are found in elliptical galaxies, which are thought to result from the merger of two spiral galaxies. Ma found, however, that mergers of elliptical galaxies themselves could produce the largest elliptical galaxies as well as supermassive black holes approaching 10 billion solar masses. These black holes can grow even larger by consuming gas left over from a merger.
Using telescopes at the Gemini and Keck observatories in Hawaii and at McDonald Observatory in Texas, McConnell and Ma obtained detailed spectra of the diffuse starlight at the centers of several massive elliptical galaxies, each the brightest galaxy in its cluster. So far, they’ve analyzed the orbital velocities of stars in two galaxies and calculated the central masses to be in the quasar range. Having such huge masses contained within a volume only a few hundred light years across led the astronomers to conclude that the masses were massive black holes.
“If all that mass were in stars, then we would see their light”, Ma said.
Modeling these massive galaxies required use of state-of-the-art supercomputers at the Texas Advanced Computing Center.
“For an astronomer, finding these insatiable black holes is like finally encountering people nine feet tall, whose great height had only been inferred from fossilized bones. How did they grow so large?” Ma said. “This rare find will help us understand whether these black holes had very tall parents or ate a lot of spinach.”