what is the name of the black hole located in the centre of our galaxy
Supermassive black hole


allowed for in modern computer generated images such as the example presented here, based on a plausible model for the supermassive black hole in Sgr A* at the centre of our own galaxy. However the resolution provided by presently available telescope technology is still insufficient to confirm such predictions directly. What already has been observed directly in many systems are the lower non-relativistic velocities of matter orbiting further out from what are presumed to be black holes. Direct Doppler measures of water masers surrounding the nuclei of nearby galaxies have revealed a very
2715880
Sigma (cosmology)


. They expected no correlation what so ever. But when plotting their results on a Scatter diagram and drawing a line of best fit they ended up with a positive correlation. It appeared that the heavier the black hole at the centre, the faster the stars within the galaxy travelled. This property helped them realise that a Supermassive black hole nucleus must be the reason for the galaxies in some way. They saw that the clouds of gas before the galaxies compressed forming a black hole, the black hole would produce phenomenal amounts of
2158979
European Southern Observatory


from the region at regular intervals. While the cause of this phenomenon is unknown, observers have suggested that the black hole may be spinning rapidly. The VLT has also peered into the centre of galaxies beyond our own, where clear signs of activity produced by supermassive black holes are found. In the active galaxy NGC 1097, a complex network of filaments spiraling from the main part of the galaxy to its centre was seen in great detail. Gamma-ray bursts (GRBs) are bursts of highly energetic gamma rays lasting from
9606575
Sigma (cosmology)


Sigma in cosmology is a property of galaxies used when trying to work out the mystery of galaxies and their supermassive black holes. In the late 1990s the NUKER experts had made observations with a spectroscope of two galaxies, one of an active galaxy with an active galactic nucleus called NGC10-68 and a dormant galaxy next door to us named Andromeda. The observations are shown. The light from the centre in Andromeda galaxy was distorted proving the existence of super-massive black holes. Other observations proved most galaxies had a similar centre
2158977
Astronomical spectroscopy


where none were expected. It was soon realised that what was observed was a normal galactic spectrum, but highly red shifted. These were named "quasi-stellar radio sources", or quasars, by Hong-Yee Chiu in 1964. Quasars are now thought to be galaxies formed in the early years of our universe, with their extreme energy output powered by super-massive black holes. The properties of a galaxy can also be determined by analyzing the stars found within them. NGC 4550, a galaxy in the Virgo
770646
Sigma (cosmology)


whether it be active or dormant. They then realised that the black holes must have something to do with a galaxy's formation, so they turned to something they thought was useless: the speed of the stars around the edge of the galaxy. This is sigma, the speed of the stars at the edge of the galaxy supposedly unaffected by the mass of the black hole at the centre. The NUKER team calculated the sigma of several stars in different galaxies and the mass of the black hole at the (nucleus) centre
2158978
Laser Interferometer Space Antenna


Gravitational waves are caused by energetic events in the universe and, unlike any other radiation, can pass unhindered by intervening mass. Launching LISA will add a new sense to scientists' perception of the universe and enable them to study phenomena that are invisible in normal light. Potential sources for signals are merging massive black holes at the centre of galaxies, massive black holes orbited by small compact objects, known as extreme mass ratio inspirals, binaries of compact stars in our Galaxy, and possibly other sources of cosmological origin, such as
5899542
Spiral galaxy


down to lower mass and luminosity); others simply appear as higher density centers of disks, with properties similar to disk galaxies. Many bulges are thought to host a supermassive black hole at their centers. In our own galaxy, for instance, the object called Sagittarius A* is believed to be a supermassive black hole. There are many lines of evidence for the existence of black holes in spiral galaxy centers, including the presence of active nuclei in some spiral galaxies, and dynamical measurements that find large compact central masses in
228662
NGC 2768


NGC 2768 is a lenticular galaxy located in the constellation of Ursa Major. It is at a distance of 65 million light years from Earth. NGC 2768 is an example of a Seyfert galaxy, an object with a supermassive black hole at its centre. A dusty structure is encircling the centre of the galaxy, forming a knotted ring around the galaxy's brightly glowing middle. This ring lies perpendicular to the plane of NGC 2768 itself, stretching up and out of the galaxy. The dust in NGC 2768 forms an intricate network
17871389
Quasar


. The matter accreting onto the black hole is unlikely to fall directly in, but will have some angular momentum around the black hole that will cause the matter to collect into an accretion disc. Quasars may also be ignited or re-ignited when normal galaxies merge and the black hole is infused with a fresh source of matter. In fact, it has been suggested that a quasar could form when the Andromeda Galaxy collides with our own Milky Way galaxy in approximately 3–5 billion years. In the 1980s, unified models were developed
5542616
Intermediate-mass black hole


An intermediate-mass black hole (IMBH) is a class of black hole with mass in the range 10-10 solar masses: significantly more than stellar black holes but less than the 10-10 solar mass supermassive black holes. Several IMBH candidate objects have been discovered in our galaxy and others nearby, based on indirect gas cloud velocity and accretion disk spectra observations of various evidentiary strength. The strongest evidence for IMBHs comes from a few low-luminosity active galactic nuclei. Due to their activity, these galaxies almost certainly
21250043
RX J1242−11


RX J1242.6−1119A (often abbreviated RX J1242−11) is an elliptical galaxy located approximately 200 megaparsecs (about 650 million light-years) from Earth. According to current interpretations of X-ray observations made by the Chandra X-ray Observatory and XMM-Newton, the centre of this galaxy is a 100 million solar mass supermassive black hole which was observed to have tidally disrupted a star (in 1992 or shortly before). The discovery is widely considered to be the first strong evidence of a supermassive black hole ripping apart a star
13845931
Luminous infrared galaxy


class of objects discovered by WISE, extremely luminous infrared galaxies, or ELIRGs. Light from the WISE J224607.57-052635.0 galaxy has traveled 12.5 billion years. The black hole at its center was billions of times the mass of our sun when the universe was a tenth (1.3 billion years) of its present age of 13.8 billion years. There are three reasons the black holes in the ELIRGs could be massive. First, the embryonic black holes might be bigger than thought possible. Second, the Eddington limit was exceeded. When
20463819
Intergalactic star


expelled from their host galaxies during a galactic collision between two giant ellipticals, as their supermassive black hole centres merged. Another hypothesis, that is not mutually exclusive to the galactic collisions hypothesis, is that intergalactic stars were ejected from their galaxy of origin by a close encounter with the supermassive black hole in the galaxy center, should there be one. In such a scenario, it is likely that the intergalactic star(s) was originally part of a multiple star system where the other stars were pulled into the supermassive black hole and the
14224536
Hen 2-10


Hen 2-10, also known as He 2-10 and Henize 2-10, is a dwarf starburst galaxy located 34 million light years away in the constellation of Pyxis. The galaxy is believed to be an early stage starburst galaxy. A black hole was later discovered near the center of the dwarf galaxy, suggesting that the black holes found at the center of most large galaxies may have formed before the galaxies themselves. Recent estimates have placed the mass of this black hole around , and the mass of the entire
14778597
Stellar black hole


However, this claim was subsequently retracted. The more likely mass is 5–10 solar masses. There is observational evidence for two other types of black holes, which are much more massive than stellar black holes. They are intermediate-mass black holes (in the centre of globular clusters) and supermassive black holes in the centre of the Milky Way and other galaxies. Stellar black holes in close binary systems are observable when matter is transferred from a companion star to the black hole. The energy release in the fall toward the compact
21250947
Multi-unit spectroscopic explorer


in on the region around the super-massive black hole at the centre of massive galaxies. It is hoped that this will help astronomers understand the process by which these giants formed - likely through a merging process whereby two black holes coalesce to form a more massive end product and at the same time perturbing the stellar orbits in the centre of the galaxy. At higher redshift MUSE will provide the power to construct maps of the distribution of metals in galaxies and at the same time provide constraints on the dynamical structure of these objects
1075112
Andromeda Galaxy


Barnard "et al." hypothesized that these are candidate black holes or neutron stars, which are heating the incoming gas to millions of kelvins and emitting X-rays. Neutron stars and black holes can be distinguished mainly by measuring their masses. An observation campaign of NuSTAR space mission identified 40 objects of this kind in the galaxy. In 2012, a microquasar, a radio burst emanating from a smaller black hole, was detected in the Andromeda Galaxy. The progenitor black hole is located near the galactic center and has about
21869875
NGC 2768


of knots and filaments. In the centre of the galaxy are two tiny, S-shaped symmetric jets. These two flows of material travel outwards from the galactic centre along curved paths, and are masked by the tangle of dark dust lanes that spans the body of the galaxy. These jets are a sign of a very active centre, where lies a supermassive black hole. This speeds up and sucks in gas from the nearby space, creating a stream of material swirling inwards towards the black hole known as an accretion disc
17871390
Radio Galaxy Zoo


Radio Galaxy Zoo (RGZ) is an internet crowdsourced citizen science project that seeks to locate supermassive black holes in distant galaxies. It is hosted by the web portal Zooniverse. The scientific team want to identify black hole/jet pairs and associate them with the host galaxies. Using a large number of classifications provided by citizen scientists they hope to build a more complete picture of black holes at various stages and their origin. It was initiated in 2010 by Ray Norris in collaboration with the Zooniverse team, and was driven by the
5818916
Messier 74


intermediate-mass black hole. This would be a rather uncommon class of black holes, somewhere in between in size of stellar black holes and the massive black holes theorized to reside in the center of many galaxies. Because of this, they are believed to form not from single supernovae, but possibly from a number of lesser stellar black holes in a star cluster. The X-ray source is identified as CXOU J013651.1+154547. Messier 74 is located 1.5° east-northeast of Eta Piscium. This galaxy has the
7937543
American Astronomical Society 215th meeting


4 million solar masses, is located in the center of our own Milky Way galaxy. As the universe has evolved, galaxies often collide and merge, creating larger galaxies. This has led to the supposition that galaxies in mid-merge should have a two great black holes (a pair) orbiting one another. Expectations were, that this should be a common observation, hand in hand with mid merge collisions. However, observation has not validated this supposition; only a few orbiting pairs had been found. When observation did
551949
Phoenix Cluster


extends to over 1.1 million light years from the center, making it one of the largest galaxies known. It is 22 times the diameter of our galaxy, and its starburst activity suggests that the galaxy is still growing larger. The Phoenix Cluster is also producing more X-rays than any other known massive cluster. The central elliptical cD galaxy of this cluster hosts an active galactic nucleus, which is powered by a central supermassive black hole. The central black hole has an estimated mass on the order of 20 billion . This
18430243
Cosmological principle


any human observer at any location on Earth: as Andrew Liddle puts it, "the cosmological principle [means that] the universe looks the same whoever and wherever you are." The qualification is that variation in physical structures can be overlooked, provided this does not imperil the uniformity of conclusions drawn from observation: the Sun is different from the Earth, our galaxy is different from a black hole, some galaxies advance toward rather than recede from us, and the universe has a "foamy" texture of galaxy clusters and
9011992
Supermassive black hole


with up to 10 , or a large number of smaller black holes with masses below 10 . Dynamical evidence for a massive dark object was found at the core of the active elliptical galaxy Messier 87 in 1978, initially estimated at . Discovery of similar behavior in other galaxies soon followed, including the Andromeda Galaxy in 1984 and the Sombrero Galaxy in 1988. Donald Lynden-Bell and Martin Rees hypothesized in 1971 that the center of the Milky Way galaxy would contain a massive black hole. Sagittarius A* was discovered and named on
2715865
Supermassive black hole


A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, containing a mass of the order of hundreds of thousands to billions of times the mass of the Sun (). Black holes are a class of astronomical object that have undergone gravitational collapse, leaving behind spheroidal regions of space from which nothing can escape, not even light. Observational evidence indicates that nearly all large galaxies contain a supermassive black hole, located at the galaxy's center. In the case of the Milky Way, the
2715856
Intermediate-mass black hole


object shown in the figure, can be fit equally well without a massive central object. Additional evidence for the existence of IMBHs can be obtained from observation of gravitational radiation, emitted from a binary containing an IMBH and a compact remnant or another IMBH. Finally, the M-sigma relation predicts the existence of black holes with masses of 10 to 10 solar masses in low-luminosity galaxies. In November 2004 a team of astronomers reported the discovery of GCIRS 13E, the first intermediate-mass black hole in our galaxy,
21250046
Quasar


mapping. Several dozen nearby large galaxies, including our own Milky Way galaxy, that do not have an active center and do not show any activity similar to a quasar, are confirmed to contain a similar supermassive black hole in their nuclei (galactic center). Thus it is now thought that all large galaxies have a black hole of this kind, but only a small fraction have sufficient matter in the right kind of orbit at their center to become active and power radiation in such a way as to be seen as quasars
5542614
Hercules A


, however, plasma jets over one million light years long appear. Detailed analyses indicate that the galaxy is actually over 1,000 times more massive (approx. 10 solar masses) than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive (approx. 4 billion solar masses) than the black hole at our Milky Way's center, one of the largest known. The physics that creates the jets is poorly understood, with a likely energy source being matter ejected perpendicular to the accretion disc of the
14928112
The Whole Shebang: A State-of-the-Universe(s) Report


that there is at least one, if not several, Black Holes in the middle of our own Milky Way galaxy. Visible light is unable to reach our telescopes from the center of the galaxy, so higher radio ways are used for "viewing." He suggests that by searching for Bekenstein-Hawking radiation then we might be able to find these Black Holes. According to Anthony Campbell's book review Ferris explains why cosmologists have their present-day philosophies. He points out that Ferris shows a mutual relationship between the very
19744299
Stellar black hole


of black hole natal kicks. The velocity distribution of black hole natal kicks seems similar to that of neutron star kick velocities. One might have expected that it would be the momenta that were the same with black holes receiving lower velocity than neutron stars due to their higher mass but that doesn't seem to be the case, which may be due to the fall-back of asymmetrically expelled matter increasing the momentum of the resulting black hole. Our Milky Way galaxy contains several stellar-mass Black Hole Candidates (BHCs) which
21250951
Leo Cluster


probably younger than most comparable clusters in the universe and evolve at a different pace. Most dense galaxy clusters are composed mostly of elliptical galaxies. The Leo Cluster, however, mostly contains spiral galaxies, suggesting that it is much younger than other comparable clusters, such as the Coma Cluster. It is also home to one of the universe's largest known black holes, which lies in the center of NGC 3842. The black hole is 9.7 billion times more massive than our sun. It can be very difficult for stars to
15218263
NGC 6951


suggested that it is in transition form, between a Seyfert galaxy and a very-high-excitation LINER, with very strong [N II] and [S II] lines. A supermassive black hole which accretes material in the centre of the galaxy is believed to be the cause of the nuclear activity. The upper mass limit of the supermassive black hole at the centre of NGC 6951 is estimated to be between 6 and 14 million based on velocity dispersion. Molecular gas, most probably a circumnuclear dust disk or torus less
20346030
Galaxy


trillion to one hundred trillion years (10–10 years), as the smallest, longest-lived stars in our universe, tiny red dwarfs, begin to fade. At the end of the stellar age, galaxies will be composed of compact objects: brown dwarfs, white dwarfs that are cooling or cold ("black dwarfs"), neutron stars, and black holes. Eventually, as a result of gravitational relaxation, all stars will either fall into central supermassive black holes or be flung into intergalactic space as a result of
12147589
Andromeda–Milky Way collision


galactic nucleus, releasing as much energy as 100 million supernova explosions. As of 2006, simulations indicated that the Sun might be brought near the centre of the combined galaxy, potentially coming near one of the black holes before being ejected entirely out of the galaxy. Alternatively, the Sun might approach one of the black holes a bit closer and be torn apart by its gravity. Parts of the former Sun would be pulled into the black hole. Two scientists with the Harvard–Smithsonian Center for Astrophysics stated that when, and
16656862
NGC 7674


, 0.7 kpc long. The reason for this shape may be a change in the black hole spin axis due to a minor merger, the presence of a binary black hole or due to interactions with the interstellar medium. Two radio sources with characteristics similar to accreting supermassive black holes have been observed in the centre of NGC 7674, at a projected separation of 0.35 parsec. NGC 7674 falls into the family of luminous infrared galaxies, with its infrared luminosity being 10 . The luminous infrared galaxies are characterised by intense star forming activity
19553574
NGC 3367


northeast 33". The total extent of the source is approximately 12 kpc at the distance of the galaxy. More detailed observations by the Very Large Array revealed a radio jet connecting the nucleus with the southwest lobe and a circumnuclear structure with a radius of nearly 300 pc. In the centre of the galaxy lies a supermassive black hole whose mass is estimated to be (10) based on Ks bulge luminosity. The X-ray spectra of the galaxy suggested the mass of the supermassive black hole to be in the range of
18379324
NGC 1380


NGC 1380 is a lenticular galaxy located in the constellation Fornax. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 1380 is about 85,000 light years across. It was discovered by James Dunlop on September 2, 1826. It is a member of the Fornax Cluster. In the centre of NGC 1380 lies a supermassive black hole whose mass is estimated to be based on the velocity dispersion of the globular clusters of the galaxy. The nucleus of NGC
19301189
NGC 2985


black hole. The mass of the supermassive black hole at the centre of NGC 2985 is estimated to be 160 million (10) , based on stellar velocity dispersion. The velocity dispersion is anisotropic, and changes with the azimuth. The rotational speed of the galaxy at its effective radius is 222.9 ± 31.2 km/s. NGC 2985 is the brightest member of a galaxy group known as the NGC 2985 group. Other members of the group include NGC 3027, 25 arcminutes away. Other nearby galaxies include NGC 3252, and
815932
How It Began


is the center of our galaxy, site of a black hole four million times the mass of the Sun. The second third of the book examines the remote universe. Andromeda is seen as it was before humans evolved on the plains of Africa, and galaxies are all seen over time spans that dwarf our existence. The next stop is the massive Coma cluster of galaxies, a swarm of thousands of galaxies bound by invisible dark matter. This section continues with a visit to galaxies that created their stars long before the Earth formed
22002924
Pegasus (constellation)


Parsons. Another of Pegasus's galaxies is NGC 7742, a Type 2 Seyfert galaxy. Located at a distance of 77 million light-years with a redshift of 0.00555, it is an active galaxy with a supermassive black hole at its core. Its characteristic emission lines are produced by gas moving at high speeds around the central black hole. Pegasus is also noted for its more unusual galaxies and exotic objects. Einstein's Cross is a quasar that has been lensed by a foreground galaxy. The elliptical galaxy is 400 million light
1732824
S5 0014+81


hole in its center, which may be responsible for the intense activity of this blazar. In 2009, a team of astronomers using the Swift spacecraft used the luminosity output of S5 0014+81 to measure the mass of the central black hole. They found it to be about 10,000 times more massive than the black hole at the center of our galaxy, or equivalent to 40 billion solar masses. This makes it one of the most massive black holes ever discovered, more than six times the value of the black hole of
5752135
NGC 660


may indicate the presence of a super-cluster of stars located within an area of cloud of gas. The region in the centre has a vast amount of star formation, so luminous that it is considered to be a starburst galaxy. Late in 2012, this polar-ring galaxy produced an enormous outburst having a magnitude of approximately ten times brighter than a supernova explosion. The cause is not certain, but this event may have resulted from a tremendous jet being emanating from galaxy's central black hole. NGC 660 is a
19719178
Galaxy formation and evolution


galaxies). A distinguishing feature of elliptical galaxies is that the velocity of the stars does not necessarily contribute to flattening of the galaxy, such as in spiral galaxies. Elliptical galaxies have central supermassive black holes, and the masses of these black holes correlate with the galaxy's mass. Elliptical galaxies have two main stages of evolution. The first is due to the supermassive black hole growing by accreting cooling gas. The second stage is marked by the black hole stabilizing by suppressing gas cooling, thus leaving the elliptical galaxy in a
11618329
Andromeda–Milky Way collision


ping-pong ball every . Thus, it is extremely unlikely that any two stars from the merging galaxies would collide. The Milky Way and Andromeda galaxies each contain a central supermassive black hole (SMBH), these being Sagittarius A* (c. ) and an object within the P2 concentration of Andromeda's nucleus (). These black holes will converge near the centre of the newly formed galaxy over a period that may take millions of years, due to a process known as dynamical friction: As the SMBHs move relative to
16656860
Alexander Wilson (astronomer)


what hinders the fixed stars from falling upon one another", the question that Newton had posed in his "Opticks" (1704), was that the entire universe rotated around its centre. This has been found to be true of the stars of the Galaxy, the then known universe, which rotates around a central black hole. It is not true for the galaxies of the Universe which is expanding. Wilson noted that sunspots viewed near the edge of the Sun's visible disk appear depressed below the solar surface, a
14962487
Supermassive black hole


-thousandths the mass of the Milky Way. Some galaxies, however, lack any supermassive black holes in their centers. Although most galaxies with no supermassive black holes are very small, dwarf galaxies, one discovery remains mysterious: The supergiant elliptical cD galaxy A2261-BCG has not been found to contain an active supermassive black hole, despite the galaxy being one of the largest galaxies known; ten times the size and one thousand times the mass of the Milky Way. Since a supermassive black hole will only be visible while it is accreting
2715893
NGC 3982


3982 is a Seyfert 2 galaxy that spans about 30,000 light-years, about one-third of the size of our Milky Way galaxy. The galaxy is receding from us at about 1109 km/s. The galaxy is a typical spiral galaxy, similar to our Milky Way. It harbors a supermassive black hole at its core and has massive regions of star formation in the bright blue knots in the spiral arms. Supernovae are likely to be found within these regions. NGC 3982 has a high rate of star birth within
10092079
Avi Loeb


universe. In 2008, he was featured in a cover story of Smithsonian magazine on black holes and in two cover stories of Astronomy Magazine, one on the collision between the Milky Way and the Andromeda Galaxy and the second on the future state of our universe. In 2009, Loeb reviewed in a Scientific American article a new technique for imaging black hole silhouettes. In 2010 he wrote a textbook entitled "How Did the First Stars and Galaxies Form?", published by Princeton University Press. In the same year, Loeb
18613668
Triangulum Galaxy


massive stars in this galaxy matches the level of similar stars in the Large Magellanic Cloud. In 2007, a black hole about 15.7 times the mass of the Sun was detected in this galaxy using data from the Chandra X-ray Observatory. The black hole, named M33 X-7, orbits a companion star which it eclipses every 3.5 days. It is the largest stellar mass black hole known. As mentioned above, M33 is linked to M31 by several streams of neutral hydrogen and stars, which suggests that a past interaction between
20123772
GRB 090423


its demise, which would probably have signalled the birth of a black hole. The event occurred roughly 630 million years after the Big Bang, confirming that massive stellar births (and deaths) did indeed occur in the very early Universe. When the burst occurred it was 3.3 billion ly away from our position, but due to the expansion of the universe and the movement of galaxies, the originating galaxy is now 30 billion ly away. Joshua Bloom of the University of California, Berkeley, who was able to observe the location
14409739
Hubble Space Telescope


-suited to establishing the prevalence of black holes in the nuclei of nearby galaxies. While it had been hypothesized in the early 1960s that black holes would be found at the centers of some galaxies, and astronomers in the 1980s identified a number of good black hole candidates, work conducted with Hubble shows that black holes are probably common to the centers of all galaxies. The Hubble programs further established that the masses of the nuclear black holes and properties of the galaxies are closely related. The legacy of the Hubble programs on black
18598831
Galaxy Zoo


not have bulges. Many galactic bulges are thought to host a supermassive black hole at their centers: however pure disk galaxies with no bulges but with growing central black holes were found. That pure disk galaxies and their central black holes may be consistent with a relation derived from elliptical and bulge-dominated galaxies with very different formation histories implies the details of stellar galaxy evolution and dynamics may not be fundamental to the co-evolution of galaxies and black holes. It seems that these bulgeless galaxies have formed in environments isolated from other
1051071
Fuzzball (string theory)


Schwarzschild radii, which Karl Schwarzschild calculated using an entirely different mathematical technique 87 years earlier. Due to the mass-density inverse-square rule, all fuzzballs need not have unimaginable densities. There are also supermassive black holes, which are found at the center of virtually all galaxies. Sagittarius A*, the black hole at the center of our Milky Way galaxy, is 4.3 million . If fuzzball theory is correct, it has a mean density that is “only” 51 times that of gold. At 3.9 billion (
1075517
John Michell


the universe, and today astronomers believe that black holes do indeed exist at the centers of most galaxies. Similarly, Michell proposed that astronomers could detect "dark stars" by looking for star systems which behaved gravitationally like two stars, but where only one star could be seen. Michell argued that this would show the presence of a "dark star". It was an extraordinarily accurate prediction. All of the dozen candidate stellar black holes in our galaxy (the Milky Way) are in X-ray compact binary systems.
21720586
Abell 2597


Abell 2597 is a galaxy cluster located about a billion light years from Earth in the constellation of Aquarius. It is a giant elliptical galaxy that is surrounded by a sprawling cluster of other galaxies. In 2018, the National Radio Astronomy Observatory (NRAO) captured cosmic weather event using the Atacama Large Millimeter/submillimeter Array (ALMA) that has never been seen before - a cluster of towering intergalactic gas clouds raining in on the supermassive black hole at the center of the huge galaxy. The black hole draws in vast store of
21430581
No Man's Sky


galaxy. They are able to guide the Traveller towards meeting Atlas, either by directing them to the location of a nearby Atlas Interface, the vessel they were previously transported to, or to a black hole that can quickly take the Traveller closer to the centre of the galaxy. After constructing the Mind Arc, the Traveller must choose whether to upload Artemis's soul into a machine aboard the Anomaly or to let them die. Regardless of the choice, they are directed by a distress beacon to another portal, where they find
15791432
Black hole


Event Horizon Telescope (EHT), run by MIT's Haystack Observatory, is an active program that directly observes the immediate environment of the event horizon of black holes, such as the black hole at the centre of the Milky Way. In April 2017, EHT began observation of the black hole in the center of Messier 87. "In all, eight radio observatories on six mountains and four continents observed the galaxy in Virgo on and off for 10 days in April 2017" to provide the data yielding the image two years
4412792
Black hole


later in April 2019. After 2 years of data processing, EHT released the first direct image of a black hole, specifically the supermassive black hole that lies in the center of the aforementioned galaxy. What is visible is not the black hole, which shows as black; gases at the edge, the event horizon, show as orange or red, defining the black hole. Astrophysicist Feryal Özel, team member, commented about this image and the theory of general relativity: Just because this first image upholds general relativity "does
4412793
NGC 4151


NGC 4151 is an intermediate spiral seyfert galaxy with weak inner ring structure located from Earth in the constellation Canes Venatici. The galaxy was first mentioned by William Herschel on March 17, 1787; it was one of the two Seyfert galaxies described in the paper which defined the term. It is one of the nearest galaxies to Earth to contain an actively growing supermassive black hole; it was speculated that the nucleus may host a binary black hole, with about 40 million and about 10 million solar masses respectively, orbiting with a 15.8-year
20133276
Quasar


in favor of the Big Bang cosmology. Quasars show the locations where massive black holes are growing rapidly (via accretion). These black holes grow in step with the mass of stars in their host galaxy in a way not understood at present. One idea is that jets, radiation and winds created by the quasars, shut down the formation of new stars in the host galaxy, a process called 'feedback'. The jets that produce strong radio emission in some quasars at the centers of clusters of galaxies are known to
5542623
Supermassive black hole


is commonly accepted that the center of nearly every galaxy contains a supermassive black hole. The reason for this assumption is the M-sigma relation, a tight (low scatter) relation between the mass of the hole in the 10 or so galaxies with secure detections, and the velocity dispersion of the stars in the bulges of those galaxies. 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 nearby Andromeda Galaxy
2715885
Black hole


NGC 3377, NGC 4258, NGC 4889, NGC 1277, OJ 287, APM 08279+5255 and the Sombrero Galaxy. It is now widely accepted that the center of nearly every galaxy, not just active ones, contains a supermassive black hole. The close observational correlation between the mass of this hole and the velocity dispersion of the host galaxy's bulge, known as the M-sigma relation, strongly suggests a connection between the formation of the black hole and the galaxy itself. Another way that the black hole nature
4412812
NGC 7252


galaxies giant loops resemble a diagram of electrons orbiting the nucleus of an atom. The galaxy is the result of a collision of two galaxies. This collision is an opportunity for astronomers to study such mergers and to predict the future of our Milky Way after its expected collision with the Andromeda Galaxy. X-ray emissions were observed in NGC 7252. This suggests the existence of nuclear activity or an intermediate-mass black hole in the galaxy. The central region of the galaxy is home to hundreds of massive, ultra-luminous
5453544
Velocity dispersion


, the σ found for objects about the Milky Way's supermassive black hole (SMBH) is about 75 km/s. The Andromeda Galaxy (Messier 31) hosts a SMBH about 10 times larger than our own, and has a σ ≈ 160 km/s. Groups and clusters of galaxies have a wider range of velocity dispersions than smaller objects. For example, our own poor group, the Local Group, has a σ = 61±8 km/s. But "rich" clusters of galaxies, such as the
328924
Rare Earth hypothesis


, and more than half, like the Milky Way, exhibit multiple arms. According to Rare Earth, our own galaxy is unusually quiet and dim (see below), representing just 7% of its kind. Even so, this would still represent more than 200 billion galaxies in the known universe. Our galaxy also appears unusually favorable in suffering fewer collisions with other galaxies over the last 10 billion years, which can cause more supernovae and other disturbances. Also, the Milky Way's central black hole seems to have neither
9835685
MeerKAT


, David Mabuza, inaugurated the MeerKAT Telescope, and unveiled an image produced by MeerKAT that revealed unprecedented detail of the region surrounding the supermassive black hole at the centre of our Milky Way Galaxy. The 64 MeerKAT antennas will be incorporated into Phase 1 of the SKA Mid Frequency Array once the 133 SKA dishes have been built and commissioned on the Karoo site, resulting in a total of 197 antennas for the SKA array. All of the infrastructure currently associated with MeerKAT will be transferred to the SKA array. The KAPB has the
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Max Planck Institute for Extraterrestrial Physics


regularly. "Under construction:" "Proposed projects:" In the past decades, several scientists at the MPE received international awards for their discoveries and work. The following list contains selected awards; it is updated regularly. On 8 February 2010, the oldest Dutch university in Leiden bestowed an honorary doctorate on Reinhard Genzel, astrophysicist and director at the MPE, for "his ground-breaking research into interstellar matter and the central regions of galaxies, in particular the evidence for a black hole at the centre of our own
21518397
List of most massive black holes


commonly accepted that the center of nearly every galaxy contains a supermassive black hole. 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. 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. Although SMBHs are currently theorized to exist
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Elliptical galaxy


contain a black hole at the center. The mass of the black hole is tightly correlated with the mass of the galaxy, evidenced through correlations such as the M–sigma relation which relates the velocity dispersion of the surrounding stars to the mass of the black hole at the center. Elliptical galaxies are preferentially found in galaxy clusters and in compact groups of galaxies. Unlike flat spiral galaxies with organization and structure, elliptical galaxies are more three-dimensional, without much structure, and their stars are in somewhat random orbits around the
228648
Laser Interferometer Space Antenna


gravitational-wave spectrum, which contains many astrophysically interesting sources. Such a detector would observe signals from binary stars within our galaxy (the Milky Way); signals from binary supermassive black holes in other galaxies; and extreme-mass-ratio inspirals and bursts produced by a stellar-mass compact object orbiting a supermassive black hole. There are also more speculative signals such as signals from cosmic strings and primordial gravitational waves generated during cosmological inflation. LISA will be able to detect the nearly monochromatic gravitational waves emanating of close binaries consisting
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Pictor


around 485 million light-years away, is a double-lobed radio galaxy and a powerful source of radio waves in the Southern Celestial Hemisphere. From a supermassive black hole at its centre, a relativistic jet shoots out to an X-ray hot spot 800,000 light years away. SPT-CL J0546-5345 is a massive galaxy cluster located around 7 billion light-years away with a mass equivalent to approximately 800 trillion suns. GRB 060729 was a gamma-ray burst that was first observed on 29 July 2006.
1475476
Spin-flip


A black hole spin-flip occurs when the spin axis of a rotating black hole undergoes a sudden change in orientation due to absorption of a second (smaller) black hole. Spin-flips are believed to be a consequence of galaxy mergers, when two supermassive black holes form a bound pair at the center of the merged galaxy and coalesce after emitting gravitational waves. Spin-flips are significant astrophysically since a number of physical processes are associated with black hole spins; for instance, jets in active galaxies are believed to be
14511227
M–sigma relation


many astronomers to imply that supermassive black holes are fundamental components of galaxies. Prior to about 2000, the main concern had been the simple detection of black holes, while afterward the interest changed to understanding the role of supermassive black holes as a critical component of galaxies. This led to the main uses of the relation to estimate black hole masses in galaxies that are too distant for direct mass measurements to be made, and to assay the overall black hole content of the Universe. The tightness of the M–σ relation suggests
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M–sigma relation


, presumably because the data on which they were based were of insufficient quality to resolve the black hole's dynamical sphere of influence. The mean ratio of black hole mass to bulge mass in big early-type galaxies is now believed to be approximately 1:200, and increasingly smaller as one moves to less massive galaxies. A common use of the "M"–"σ" relation is to estimate black hole masses in distant galaxies using the easily measured quantity σ. Black hole masses in thousands of galaxies have been estimated in this way. The
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Luminous infrared galaxy


gas faster than thought possible, if the black hole is not spinning fast. If a black hole spins slowly, it will not repel its gas absorption as much. A slow-spinning black hole can absorb more matter than a fast-spinning black hole. The massive black holes in ELIRGs could be absorbing matter for a longer time. Twenty new ELIRGs, including the most luminous galaxy found to date, have been discovered. These galaxies were not found earlier because of their distance, and because dust converts their visible light
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Black hole


black hole that may be millions or billions of times more massive than the Sun; a disk of gas and dust called an accretion disk; and two jets perpendicular to the accretion disk. Although supermassive black holes are expected to be found in most AGN, only some galaxies' nuclei have been more carefully studied in attempts to both identify and measure the actual masses of the central supermassive black hole candidates. Some of the most notable galaxies with supermassive black hole candidates include the Andromeda Galaxy, M32, M87, NGC 3115,
4412811
Radio Galaxy Zoo


, RGZ will measure the relative populations and properties of host galaxies; processes that might also provide an avenue for finding radio structures that are rare and extreme. On the International Centre for Radio Astronomy Research (ICRAR) website, an article from September 2015 named "Volunteer black hole hunters as good as the experts" explains how citizen scientists are as good as professionals at RGZ's tasks. The research team tested trained citizen scientists and ten professional astronomers using a hundred images to help quantify the quality of the data gathered. As
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NGC 7418


end of the bar. The galaxy has four grand design spiral arms. Their inner parts have knots while the outermost are smooth. The galaxy is seen with an inclination of 42 degrees. In the centre of NGC 7418 is believed to lie a supermassive black hole with an estimated mass between 1 and 15 million (10 , based on the spiral pitch angle. The centre of the galaxy has also been found to host a massive stellar cluster, with an estimated mass of nearly 60 million (10) . The existence of
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Central massive object


Central massive object (CMO) refers to a mass concentration at the center of a galaxy. It can be either a supermassive black hole or a nuclear star cluster. The most massive galaxies are thought to always contain a supermassive black hole (SBH); these galaxies do not contain nuclear star clusters, and the CMO is identified with the SBH. Fainter galaxies usually contain a nuclear star cluster (NSC). In most of these galaxies, it is not known whether a supermassive black hole is present, and the CMO
19151707
Binary black hole


than the combined power of all light radiated by all the stars in the observable universe put together. Supermassive binary black hole candidates have been found, but not yet categorically proven. Supermassive black-hole binaries are believed to form during galaxy mergers. Some likely candidates for binary black holes are galaxies with double cores still far apart. An example double nucleus is NGC 6240. Much closer black-hole binaries are likely in single core galaxies with double emission lines. Examples include SDSS J104807.74+005543.5 and EGSD2 J142033.66 525917.5. Other
11922691
New Technology Telescope


contributing to the observations of the first solar-like oscillations in another star, and breaking many distance records by finding new galaxies in the far-away Universe. Most recently, the NTT helped detect a disc around a massive young star, solving the mystery of star formation in massive stars, and its observations were crucial to determine how asteroids are modified by solar wind. Perhaps most significantly, NTT observations of stars orbiting the centre of our Milky Way helped determine the mass and the radius of its supermassive black hole, effectively
920472
Ursa Major


has a halo of globular clusters, indicating its age and relative stability. NGC 3079 is a starburst spiral galaxy located 52 million light-years from Earth. It has a horseshoe-shaped structure at its center that indicates the presence of a supermassive black hole. The structure itself is formed by superwinds from the black hole. NGC 3310 is another starburst spiral galaxy located 50 million light-years from Earth. Its bright white color is caused by its higher than usual rate of star formation, which began 100 million years ago
13187169
NGC 1395


NGC 1395 is an elliptical galaxy located in the constellation Eridanus. It is located at a distance of circa 75 million light years from Earth, which, given its apparent dimensions, means that NGC 1395 is about 130,000 light years across. It was discovered by William Herschel on November 17, 1784. It is a member of the Eridanus Cluster. In the centre of NGC 1395 lies a supermassive black hole whose mass is estimated to be (10) based on the M–sigma relation or between 100 and 257 million (
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M–sigma relation


small. It is unclear whether the lack of black hole detections in many galaxies implies that these galaxies do not contain black holes; or that their masses are significantly below the value implied by the M–σ relation; or that the data are simply too poor to reveal the presence of the black hole. The smallest supermassive black hole with a well-determined mass has . The existence of black holes in the mass range ("intermediate-mass black holes") is predicted by the M–σ relation in low
3719640
Sagittarius A


evidence there is a supermassive black hole at the center of the galaxy. Sagittarius A* (abbreviated Sgr A*) is agreed to be the most plausible candidate for the location of this supermassive black hole. The Very Large Telescope and Keck Telescope detected stars orbiting Sgr A* at speeds greater than that of any other stars in the galaxy. One star, designated S2, was calculated to orbit Sgr A* at speeds of over 5,000 kilometers per second at its closest approach. A gas cloud, G2, passed through
17837788
NGC 3511


seen across the spiral pattern. The bulge appears elliptical and is weak. The galaxy is seen at a high inclination, estimated to be 70°. In the centre of the galaxy lies a supermassive black hole, whose mass is estimated to be 10 (1.3 - 6.2 million) , based on the pitch angle of the spiral arms. The galaxy had been classified as a type 1 Seyfert galaxy, however it features only narrow emission lines, and has been reclassified as a HII region galaxy. The Infrared Spectograph (IRS
21749801
Rossi X-ray Timing Explorer


hole named M82 X-1. In February 2006, data from RXTE was used to prove that the diffuse background X-ray glow in our galaxy comes from innumerable, previously undetected white dwarfs and from other stars' coronae. In April 2008, RXTE data was used to infer the size of the smallest known black hole. RXTE ceased science operations on 3 January 2012. NASA scientists said that the decommissioned RXTE would re-enter the Earth's atmosphere "between 2014 and 2023". Later it became clear that the satellite would
20282541
NGC 1386


supermassive black hole in the galactic centre. The black hole in the centre of NGC 1386 is estimated to be based on stellar velocity dispersion. The central region of NGC 1386 has three distinct kinematic components. The first has low velocity dispersion (approximately 90 km/s) and is identified as gas rotating in the galaxy disk. The second is observed in the inner 150 pc around the continuum peak and has two components, one redshifted and one blueshifted, which are identified as a bipolar outflow with an outflow rate of 0.1
21443581
Intermediate-mass black hole


contain accreting black holes, and in some cases the black hole masses can be estimated using the technique of reverberation mapping. For instance, the spiral galaxy NGC 4395 at a distance of about 4 Mpc appears to contain a black hole with mass of about solar masses. Some ultra-luminous X ray sources (ULXs) in nearby galaxies are suspected to be IMBHs, with masses of a hundred to a thousand solar masses. The ULXs are observed in star-forming regions (e.g., in starburst galaxy M82), and
21250044
Supermassive black hole


galaxy NGC 1277, which lies 220 million light-years away in the constellation Perseus. The putative black hole has approximately 59 percent of the mass of the bulge of this lenticular galaxy (14 percent of the total stellar mass of the galaxy). Another study reached a very different conclusion: this black hole is not particularly overmassive, estimated at between with being the most likely value. On February 28, 2013 astronomers reported on the use of the NuSTAR satellite to accurately measure the spin of a supermassive black hole for the
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Active galactic nucleus


quasar activity on galaxy evolution. For a long time it has been argued that an AGN must be powered by accretion of mass onto massive black holes (10 to 10 times the Solar mass). AGN are both compact and persistently extremely luminous. Accretion can potentially give very efficient conversion of potential and kinetic energy to radiation, and a massive black hole has a high Eddington luminosity, and as a result, it can provide the observed high persistent luminosity. Supermassive black holes are now believed to exist in the centres of most
10457226
Stuart L. Shapiro


the development of black holes, gravitational waves from the inspiral of neutron stars and black holes in binary systems, the dynamics of large N-body, cosmological questions (big bang nucleosynthesis), and neutrino astrophysics. He has simulated the spectrum of the radiation that develops when gas from an accretion disk falls onto a black hole or neutron star and the destruction and swallowing up of stars by a supermassive black hole in the galaxy. Additionally, the collision and merging of black holes and the development of black holes in galaxies from
17843503
Supermassive black hole


constrained to a radius of 0.13 parsecs. They noted that a swarm of solar mass black holes within a radius this small would not survive for long without undergoing collisions, making a supermassive black hole the sole viable candidate. On April 10, 2019, the Event Horizon Telescope project released the first image of a black hole, in the center of the galaxy Messier 87. The origin of supermassive black holes remains an open field of research. Astrophysicists agree that once a black hole is in place in the center of a galaxy
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Swift J1745-26


Swift J1745-26 is a stellar-mass black hole located a few degrees from the center of the Milky Way galaxy toward the constellation Sagittarius. It was discovered by NASA's Swift satellite on September 16, 2012 due to the detection of an X-ray nova. The pattern of X-rays from the nova indicated that the central object was a black hole. Its name arises from the coordinates of its sky position. While astronomers do not know its precise distance, they think the object resides about 20,000 to 30,000
4356902
Hypercompact stellar system


the gravitational waves are not emitted isotropically, some momentum is imparted to the coalescing black holes, and they feel a recoil, or "kick," at the moment of coalescence. Computer simulations suggest that the kick can be as large as formula_1, which exceeds escape velocity from the centres of even the most massive galaxies. Stars that are orbiting around the SMBH at the moment of the kick will be dragged along with the SMBH, providing their orbital velocity exceeds the kick velocity . This is what determines the size of the
17012902
Dwarf galaxy


during the Dark Ages within the first billion years after the big bang. More than 20 known dwarf galaxies orbit the Milky Way, and recent observations have also led astronomers to believe the largest globular cluster in the Milky Way, Omega Centauri, is in fact the core of a dwarf galaxy with a black hole at its centre, which was at some time absorbed by the Milky Way. In astronomy, a blue compact dwarf galaxy (BCD galaxy) is a small galaxy which contains large clusters of young, hot, massive
7866626
M60-UCD1


exceeds 100 km/s, due to the gravity of a dense mass concentration. The galactic nucleus contains a bright and variable X-ray source, presumably a supermassive black hole with a mass of 20 million solar masses (15% of the mass of the entire galaxy). With this proportion of the mass of the black hole to that of the whole galaxy, it is one of the most black hole dominated galaxies known. M60-UCD1 is believed to be the stripped core of a much more massive galaxy, whose mass
2698962
NGC 1549


NGC 1549 is an elliptical galaxy located in the constellation Dorado. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 1549 is about 75,000 light years across. NGC 1549 was discovered by John Herschel on 6 December 1835 and may have been observed by James Dunlop in 1826. It is a member of the Dorado Group. In the centre of NGC 1549 is expected to lie a supermassive black hole, whose mass is estimated to be between 390 and
2540271
NGC 5033


professional astronomers. NGC 5033 contains a Seyfert nucleus, a type of active galactic nucleus. Like many other active galactic nuclei, this galaxy's nucleus is thought to contain a supermassive black hole. The bright emission seen in visible light (as well as other wavebands) is partially produced by the hot gas in the environment around this black hole. Integral field spectroscopic observations of the center of NGC 5033 indicate that the Seyfert nucleus is not located at the kinematic center of the galaxy (the point around which the stars in the
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