633:. These objects show nuclear and extended radio emission. Their other AGN properties are heterogeneous. They can broadly be divided into low-excitation and high-excitation classes. Low-excitation objects show no strong narrow or broad emission lines, and the emission lines they do have may be excited by a different mechanism. Their optical and X-ray nuclear emission is consistent with originating purely in a jet. They may be the best current candidates for AGN with radiatively inefficient accretion. By contrast, high-excitation objects (narrow-line radio galaxies) have emission-line spectra similar to those of Seyfert 2s. The small class of broad-line radio galaxies, which show relatively strong nuclear optical continuum emission probably includes some objects that are simply low-luminosity radio-loud quasars. The host galaxies of radio galaxies, whatever their emission-line type, are essentially always ellipticals.
595:/QSOs. These are essentially more luminous versions of Seyfert 1s: the distinction is arbitrary and is usually expressed in terms of a limiting optical magnitude. Quasars were originally 'quasi-stellar' in optical images as they had optical luminosities that were greater than that of their host galaxy. They always show strong optical continuum emission, X-ray continuum emission, and broad and narrow optical emission lines. Some astronomers use the term QSO (Quasi-Stellar Object) for this class of AGN, reserving 'quasar' for radio-loud objects, while others talk about radio-quiet and radio-loud quasars. The host galaxies of quasars can be spirals, irregulars or ellipticals. There is a correlation between the quasar's luminosity and the mass of its host galaxy, in that the most luminous quasars inhabit the most massive galaxies (ellipticals).
627:) classes are distinguished by rapidly variable, polarized optical, radio and X-ray emission. BL Lac objects show no optical emission lines, broad or narrow, so that their redshifts can only be determined from features in the spectra of their host galaxies. The emission-line features may be intrinsically absent or simply swamped by the additional variable component. In the latter case, emission lines may become visible when the variable component is at a low level. OVV quasars behave more like standard radio-loud quasars with the addition of a rapidly variable component. In both classes of source, the variable emission is believed to originate in a relativistic jet oriented close to the line of sight. Relativistic effects amplify both the luminosity of the jet and the amplitude of variability.
1067:
narrow-line radio galaxies show no nuclear optical continuum or reflected X-ray component, although they do occasionally show polarized broad-line emission). The large-scale radio structures of these objects provide compelling evidence that the orientation-based unified models really are true. X-ray evidence, where available, supports the unified picture: radio galaxies show evidence of obscuration from a torus, while quasars do not, although care must be taken since radio-loud objects also have a soft unabsorbed jet-related component, and high resolution is necessary to separate out thermal emission from the sources' large-scale hot-gas environment. At very small angles to the line of sight, relativistic beaming dominates, and we see a blazar of some variety.
588:. Seyferts were the earliest distinct class of AGN to be identified. They show optical range nuclear continuum emission, narrow and occasionally broad emission lines, occasionally strong nuclear X-ray emission and sometimes a weak small-scale radio jet. Originally they were divided into two types known as Seyfert 1 and 2: Seyfert 1s show strong broad emission lines while Seyfert 2s do not, and Seyfert 1s are more likely to show strong low-energy X-ray emission. Various forms of elaboration on this scheme exist: for example, Seyfert 1s with relatively narrow broad lines are sometimes referred to as narrow-line Seyfert 1s. The host galaxies of Seyferts are usually spiral or irregular galaxies.
1096:
neighbours of hundreds to thousands of AGN have shown that the neighbours of
Seyfert 2s are intrinsically dustier and more star-forming than Seyfert 1s and a connection between AGN type, host galaxy morphology and collision history. Moreover, angular clustering studies of the two AGN types confirm that they reside in different environments and show that they reside within dark matter halos of different masses. The AGN environment studies are in line with evolution-based unification models where Seyfert 2s transform into Seyfert 1s during merger, supporting earlier models of merger-driven activation of Seyfert 1 nuclei.
144:
1071:
purely from a jet, with no heavily absorbed nuclear component in general. These objects cannot be unified with quasars, even though they include some high-luminosity objects when looking at radio emission, since the torus can never hide the narrow-line region to the required extent, and since infrared studies show that they have no hidden nuclear component: in fact there is no evidence for a torus in these objects at all. Most likely, they form a separate class in which only jet-related emission is important. At small angles to the line of sight, they will appear as BL Lac objects.
504:, the accreting matter does not form a thin disc and consequently does not efficiently radiate away the energy that it acquired as it moved close to the black hole. Radiatively inefficient accretion has been used to explain the lack of strong AGN-type radiation from massive black holes at the centres of elliptical galaxies in clusters, where otherwise we might expect high accretion rates and correspondingly high luminosities. Radiatively inefficient AGN would be expected to lack many of the characteristic features of standard AGN with an accretion disc.
4813:
472:, and fast outflows that emerge in opposite directions from close to the disc. The direction of the jet ejection is determined either by the angular momentum axis of the accretion disc or the spin axis of the black hole. The jet production mechanism and indeed the jet composition on very small scales are not understood at present due to the resolution of astronomical instruments being too low. The jets have their most obvious observational effects in the radio waveband, where
1032:
5643:
4666:
4678:
582:(LINERs). As the name suggests, these systems show only weak nuclear emission-line regions, and no other signatures of AGN emission. It is debatable whether all such systems are true AGN (powered by accretion on to a supermassive black hole). If they are, they constitute the lowest-luminosity class of radio-quiet AGN. Some may be radio-quiet analogues of the low-excitation radio galaxies (see below).
5653:
3869:
1054:
some of the nuclear emission into our line of sight, allowing us to see some optical and X-ray continuum and, in some cases, broad emission lines—which are strongly polarized, showing that they have been scattered and proving that some
Seyfert 2s really do contain hidden Seyfert 1s. Infrared observations of the nuclei of Seyfert 2s also support this picture.
5679:
5703:
5691:
1084:
hidden broad-line region and thus split
Seyfert 2 galaxies into two populations. The two classes of populations appear to differ by their luminosity, where the Seyfert 2s without a hidden broad-line region are generally less luminous. This suggests absence of broad-line region is connected to low Eddington ratio, and not to obscuration.
1125:
availability of cold gas near the centre of galaxies than at present. It also implies that many objects that were once luminous quasars are now much less luminous, or entirely quiescent. The evolution of the low-luminosity AGN population is much less well understood due to the difficulty of observing these objects at high redshifts.
445:
310:, at a cosmological distance) then its large redshift of 0.158 implied that it was the nuclear region of a galaxy about 100 times more powerful than other radio galaxies that had been identified. Shortly afterward, optical spectra were used to measure the redshifts of a growing number of quasars including
1103:
While it still might be valid that an obscured
Seyfert 1 can appear as a Seyfert 2, not all Seyfert 2s must host an obscured Seyfert 1. Understanding whether it is the same engine driving all Seyfert 2s, the connection to radio-loud AGN, the mechanisms of the variability of some AGN that vary between
565:
It is convenient to divide AGN into two classes, conventionally called radio-quiet and radio-loud. Radio-loud objects have emission contributions from both the jet(s) and the lobes that the jets inflate. These emission contributions dominate the luminosity of the AGN at radio wavelengths and possibly
1091:
While studies of single AGN show important deviations from the expectations of the unified model, results from statistical tests have been contradictory. The most important short-coming of statistical tests by direct comparisons of statistical samples of
Seyfert 1s and Seyfert 2s is the introduction
1039:
Unified models propose that different observational classes of AGN are a single type of physical object observed under different conditions. The currently favoured unified models are 'orientation-based unified models' meaning that they propose that the apparent differences between different types of
167:
During the first half of the 20th century, photographic observations of nearby galaxies detected some characteristic signatures of AGN emission, although there was not yet a physical understanding of the nature of the AGN phenomenon. Some early observations included the first spectroscopic detection
1053:
of obscuring material surrounding the accretion disc. It must be large enough to obscure the broad-line region but not large enough to obscure the narrow-line region, which is seen in both classes of object. Seyfert 2s are seen through the torus. Outside the torus there is material that can scatter
3727:
Ananna, Tonima Tasnim; Weigel, Anna K.; Trakhtenbrot, Benny; Koss, Michael J.; Urry, C. Megan; Ricci, Claudio; Hickox, Ryan C.; Treister, Ezequiel; Bauer, Franz E.; Ueda, Yoshihiro; Mushotzky, Richard; Ricci, Federica; Oh, Kyuseok; MejĂa-Restrepo, Julian E.; Brok, Jakob Den; Stern, Daniel; Powell,
286:
introduced Active
Galactic Nuclei in the early 1950s. At the Solvay Conference on Physics in 1958, Ambartsumian presented a report arguing that "explosions in galactic nuclei cause large amounts of mass to be expelled. For these explosions to occur, galactic nuclei must contain bodies of huge mass
1095:
Studying neighbour galaxies rather than the AGN themselves first suggested the numbers of neighbours were larger for
Seyfert 2s than for Seyfert 1s, in contradiction with the Unified Model. Today, having overcome the previous limitations of small sample sizes and anisotropic selection, studies of
1087:
The covering factor of the torus might play an important role. Some torus models predict how
Seyfert 1s and Seyfert 2s can obtain different covering factors from a luminosity and accretion rate dependence of the torus covering factor, something supported by studies in the x-ray of AGN. The models
1057:
At higher luminosities, quasars take the place of
Seyfert 1s, but, as already mentioned, the corresponding 'quasar 2s' are elusive at present. If they do not have the scattering component of Seyfert 2s they would be hard to detect except through their luminous narrow-line and hard X-ray emission.
1107:
A study of Swift/BAT AGN published in July 2022 adds support to the "radiation-regulated unification model" outlined in 2017. In this model, the relative accretion rate (termed the "Eddington ratio") of the black hole has a significant impact on the observed features of the AGN. Black Holes with
1083:
Therefore, one cannot know whether the gas in all
Seyfert 2 galaxies is ionized due to photoionization from a single, non-stellar continuum source in the center or due to shock-ionization from e.g. intense, nuclear starbursts. Spectropolarimetric studies reveal that only 50% of Seyfert 2s show a
1070:
However, the population of radio galaxies is completely dominated by low-luminosity, low-excitation objects. These do not show strong nuclear emission lines—broad or narrow—they have optical continua which appear to be entirely jet-related, and their X-ray emission is also consistent with coming
1048:
At low luminosities, the objects to be unified are Seyfert galaxies. The unification models propose that in Seyfert 1s the observer has a direct view of the active nucleus. In Seyfert 2s the nucleus is observed through an obscuring structure which prevents a direct view of the optical continuum,
1124:
Most luminous classes of AGN (radio-loud and radio-quiet) seem to have been much more numerous in the early universe. This suggests that massive black holes formed early on and that the conditions for the formation of luminous AGN were more common in the early universe, such as a much higher
3795:
Ricci, Claudio; Trakhtenbrot, Benny; Koss, Michael J.; Ueda, Yoshihiro; Schawinski, Kevin; Oh, Kyuseok; Lamperti, Isabella; Mushotzky, Richard; Treister, Ezequiel; Ho, Luis C.; Weigel, Anna; Bauer, Franz E.; Paltani, Stephane; Fabian, Andrew C.; Xie, Yanxia; Gehrels, Neil (2017). "The close
1066:
Historically, work on radio-loud unification has concentrated on high-luminosity radio-loud quasars. These can be unified with narrow-line radio galaxies in a manner directly analogous to the Seyfert 1/2 unification (but without the complication of much in the way of a reflection component:
1088:
also suggest an accretion-rate dependence of the broad-line region and provide a natural evolution from more active engines in Seyfert 1s to more "dead" Seyfert 2s and can explain the observed break-down of the unified model at low luminosities and the evolution of the broad-line region.
1079:
In the recent literature on AGN, being subject to an intense debate, an increasing set of observations appear to be in conflict with some of the key predictions of the Unified Model, e.g. that each Seyfert 2 has an obscured Seyfert 1 nucleus (a hidden broad-line region).
1120:
objects known either in the optical or the radio spectrum, because of their high luminosity. They still have a role to play in studies of the early universe, but it is now recognised that an AGN gives a highly biased picture of the "typical" high-redshift galaxy.
598:'Quasar 2s'. By analogy with Seyfert 2s, these are objects with quasar-like luminosities but without strong optical nuclear continuum emission or broad line emission. They are scarce in surveys, though a number of possible candidate quasar 2s have been identified.
611:
Radio-loud quasars behave exactly like radio-quiet quasars with the addition of emission from a jet. Thus they show strong optical continuum emission, broad and narrow emission lines, and strong X-ray emission, together with nuclear and often extended radio
1099:
While controversy about the soundness of each individual study still prevails, they all agree on that the simplest viewing-angle based models of AGN Unification are incomplete. Seyfert-1 and Seyfert-2 seem to differ in star formation and AGN engine power.
407:. Dissipative processes in the accretion disc transport matter inwards and angular momentum outwards, while causing the accretion disc to heat up. The expected spectrum of an accretion disc peaks in the optical-ultraviolet waveband; in addition, a
333:
proposed that nearby galaxies contain supermassive black holes at their centers as relics of "dead" quasars, and that black hole accretion was the power source for the non-stellar emission in nearby Seyfert galaxies. In the 1960s and 1970s, early
1049:
broad-line region or (soft) X-ray emission. The key insight of orientation-dependent accretion models is that the two types of object can be the same if only certain angles to the line of sight are observed. The standard picture is of a
349:. AGN research encompasses observational surveys to find AGN over broad ranges of luminosity and redshift, examination of the cosmic evolution and growth of black holes, studies of the physics of black hole accretion and the emission of
377:, 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 if not all massive galaxies since the mass of the black hole correlates well with the
569:
AGN terminology is often confusing, since the distinctions between different types of AGN sometimes reflect historical differences in how the objects were discovered or initially classified, rather than real physical differences.
3109:
Wang, J. M.; Du, P.; Baldwin, J. A.; Ge, J-Q.; Ferland, G. J.; Ferland, Gary J. (2012). "Star formation in self-gravitating disks in active galactic nuclei. II. Episodic formation of broad-line regions".
1104:
the two types at very short time scales, and the connection of the AGN type to small and large-scale environment remain important issues to incorporate into any unified model of active galactic nuclei.
1576:
373:). 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
208:
published a paper in which he described observations of nearby galaxies having bright nuclei that were sources of unusually broad emission lines. Galaxies observed as part of this study included
104:
The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, the rate of gas accretion onto the black hole, the orientation of the
2069:
Padovani, P.; Alexander, D. M.; Assef, R. J.; De Marco, B.; Giommi, P.; Hickox, R. C.; Richards, G. T.; Smolčić, V.; Hatziminaoglou, E.; Mainieri, V.; Salvato, M. (November 2017).
287:
and unknown nature. From this point forward Active Galactic Nuclei (AGN) became a key component in theories of galactic evolution." His idea was initially accepted skeptically.
317:
The enormous luminosities of these quasars as well as their unusual spectral properties indicated that their power source could not be ordinary stars. Accretion of gas onto a
338:
observations demonstrated that Seyfert galaxies and quasars are powerful sources of X-ray emission, which originates from the inner regions of black hole accretion disks.
2014:
275:
sources associated with the radio emission. In photographic images, some of these objects were nearly point-like or quasi-stellar in appearance, and were classified as
496:
There exists a class of "radiatively inefficient" solutions to the equations that govern accretion. Several theories exist, but the most widely known of these is the
4488:
2605:
Garrington, S. T.; Leahy, J. P.; Conway, R. G.; Laing, R. A. (1988). "A systematic asymmetry in the polarization properties of double radio sources with one jet".
4535:
2259:
Laing, R. A.; Jenkins, C. R.; Wall, J. V.; Unger, S. W. (1994). "Spectrophotometry of a Complete Sample of 3CR Radio Sources: Implications for Unified Models".
1545:
1540:
5723:
1590:
4185:
1581:
579:
97:
in the universe and, as such, can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on
5275:
418:
up to X-ray energies. The radiation from the accretion disc excites cold atomic material close to the black hole and this in turn radiates at particular
268:
4939:
3558:
Donoso, E.; Yan, L.; Stern, D.; Assef, R. J. (2014). "The Angular Clustering of WISE-Selected AGN: Different Haloes for Obscured and Unobscured AGN".
5039:
5213:
2286:
Baum, S. A.; Zirbel, E. L.; O'Dea, Christopher P. (1995). "Toward Understanding the Fanaroff-Riley Dichotomy in Radio Source Morphology and Power".
1657:
3395:; Krongold, Y.; Fuentes-Guridi, I.; Marziani, P. (1999). "The Close Environment of Seyfert Galaxies and Its Implication for Unification Models".
353:
from AGN, examination of the properties of jets and outflows of matter from AGN, and the impact of black hole accretion and quasar activity on
2324:
Chiaberge, M.; Capetti, A.; Celotti, A. (2002). "Understanding the nature of FRII optical nuclei: a new diagnostic plane for radio galaxies".
566:
at some or all other wavelengths. Radio-quiet objects are simpler since jet and any jet-related emission can be neglected at all wavelengths.
4716:
1108:
higher Eddington ratios appear to be more likely to be unobscured, having cleared away locally obscuring material in a very short timescale.
518:
430:
close to the accretion disc, but (in a steady-state situation) this will be re-radiated at some other waveband, most likely the infrared.
3918:
4601:
2177:
Vermeulen, R. C.; Ogle, P. M.; Tran, H. D.; Browne, I. W. A.; Cohen, M. H.; Readhead, A. C. S.; Taylor, G. B.; Goodrich, R. W. (1995).
5255:
4520:
497:
385:) or with bulge luminosity. Thus, AGN-like characteristics are expected whenever a supply of material for accretion comes within the
123:
Numerous subclasses of AGN have been defined on the basis of their observed characteristics; the most powerful AGN are classified as
5344:
473:
5224:
5339:
3901:
3873:
386:
3056:
Ricci, C.; Walter, R.; Courvoisier, T. J-L.; Paltani, S. (2010). "Reflection in Seyfert galaxies and the unified model of AGN".
5260:
5056:
546:
4802:
5733:
5482:
5163:
4606:
159:
of 3C 273 appears to the left of the bright quasar, and the four straight lines pointing outward from the central source are
2742:
Ogle, P.; Whysong, D.; Antonucci, R. (2006). "Spitzer Reveals Hidden Quasar Nuclei in Some Powerful FR II Radio Galaxies".
5250:
5125:
4333:
143:
5071:
5728:
5168:
4859:
1501:
Baade, Walter; Minkowski, Rudolph (1954). "Identification of the Radio Sources in Cassiopeia, Cygnus A, and Puppis A.".
5472:
5437:
5427:
4503:
2889:
Wu, Y-Z; et al. (2001). "The Different Nature in Seyfert 2 Galaxies With and Without Hidden Broad-line Regions".
1558:
1040:
objects arise simply because of their different orientations to the observer. However, they are debated (see below).
5669:
5158:
5110:
5093:
4792:
4621:
4576:
4384:
3973:
3968:
3941:
1902:
Marconi, A.; L. K. Hunt (2003). "The Relation between Black Hole Mass, Bulge Mass, and Near-Infrared Luminosity".
5613:
5115:
5029:
4777:
4709:
4302:
2995:
Nicastro, F. (2000). "Broad Emission Line Regions in Active Galactic Nuclei: The Link with the Accretion Power".
350:
94:
3728:
Meredith C.; Caglar, Turgay; Ichikawa, Kohei; Wong, O. Ivy; Harrison, Fiona A.; Schawinski, Kevin (2022-07-01).
3505:
Villarroel, B.; Korn, A. J. (2014). "The different neighbours around Type-1 and Type-2 active galactic nuclei".
5290:
4586:
4498:
4493:
4399:
4295:
4253:
3963:
3936:
553:
366:
346:
83:
43:
5538:
1232:
Curtis, Heber D. (1918). "Descriptions of 762 Nebulae and Clusters Photographed with the Crossley Reflector".
5467:
5003:
4966:
4864:
4782:
4581:
4566:
4513:
4160:
4155:
4034:
4005:
3995:
1161:
342:
318:
87:
5656:
5229:
3670:"AGN luminosity and stellar age – two missing ingredients for AGN unification as seen with iPTF supernovae"
5497:
5385:
5370:
4922:
4812:
4736:
4084:
3983:
449:
152:
109:
2562:
Laing, R. A. (1988). "The sidedness of jets and depolarization in powerful extragalactic radio sources".
235:
was a major catalyst to understanding AGN. Some of the earliest detected radio sources are nearby active
5375:
5188:
4932:
4787:
4611:
4508:
4210:
1167:
461:
5105:
3668:
Villarroel, B.; Nyholm, A.; Karlsson, T.; Comeron, S.; Korn, A.; Sollerman, J.; Zackrisson, E. (2017).
1134:
382:
3730:"BASS. XXX. Distribution Functions of DR2 Eddington Ratios, Black Hole Masses, and X-Ray Luminosities"
5646:
5354:
5326:
5209:
5137:
4949:
4757:
4702:
4641:
4591:
4426:
4338:
4074:
3958:
3894:
3815:
3751:
3691:
3634:
3577:
3524:
3471:
3414:
3374:
3347:
3294:
3239:
3182:
3129:
3075:
3014:
2961:
2908:
2855:
2808:
2761:
2706:
2657:
2614:
2571:
2528:
2483:
2448:
2403:
2343:
2295:
2268:
2231:
2190:
2141:
2033:
1974:
1921:
1868:
1825:
1782:
1729:
1684:
1510:
1465:
1426:
1389:
1340:
1299:
1268:
1241:
1196:
480:
scales. However, they radiate in all wavebands from the radio through to the gamma-ray range via the
374:
264:
132:
5477:
5452:
5422:
5380:
5334:
4971:
4837:
4832:
4762:
4404:
4312:
4243:
4135:
4010:
1653:
378:
283:
236:
4677:
5707:
5311:
5183:
5088:
4894:
4879:
4847:
4772:
4767:
4636:
4631:
4616:
4571:
4540:
4525:
4443:
4411:
4248:
4200:
4190:
3847:
3805:
3777:
3741:
3709:
3681:
3650:
3624:
3593:
3567:
3540:
3514:
3487:
3461:
3430:
3404:
3337:
3310:
3284:
3257:
3229:
3198:
3172:
3145:
3119:
3091:
3065:
3038:
3004:
2977:
2951:
2924:
2898:
2871:
2845:
2777:
2751:
2724:
2696:
2630:
2587:
2544:
2518:
2421:
2393:
2359:
2333:
2159:
2131:
2082:
2051:
2023:
1990:
1964:
1937:
1911:
1884:
1841:
1798:
1772:
1745:
1702:
1483:
1358:
485:
412:
330:
160:
4899:
3328:
Antonucci, R. (2012). "A panchromatic review of thermal and nonthermal active galactic nuclei".
3365:
Laurikainen, E.; Salo H. (1995). "Environments of Seyfert galaxies. II. Statistical analyses".
2942:
Elitzur, M.; Shlosman I. (2006). "The AGN-obscuring Torus: The End of the Doughnut Paradigm?".
2836:
Tran, H. D. (2001). "Hidden Broad-Line Seyfert 2 Galaxies in the CFA and 12 $ \mu$ M Samples".
5457:
5447:
5442:
5178:
5142:
5130:
5083:
5024:
4993:
4983:
4917:
4669:
4651:
4626:
4596:
4475:
4317:
4307:
4290:
4222:
4051:
4017:
3978:
3931:
3839:
3831:
3769:
3030:
2120:"SDSS IV MaNGA – spatially resolved diagnostic diagrams: a proof that many galaxies are LIERs"
2100:
1645:
1631:
1155:
427:
256:
181:
131:
is an AGN with a jet pointed toward the Earth, in which radiation from the jet is enhanced by
117:
5618:
5683:
5608:
5568:
5316:
5265:
5120:
5034:
4827:
4797:
4681:
4483:
4458:
4438:
4433:
4421:
4275:
4096:
4029:
3823:
3759:
3699:
3642:
3585:
3532:
3479:
3422:
3378:
3351:
3302:
3247:
3190:
3137:
3083:
3079:
3022:
2969:
2916:
2863:
2816:
2769:
2714:
2665:
2622:
2579:
2536:
2491:
2487:
2456:
2411:
2351:
2347:
2303:
2239:
2198:
2149:
2119:
2092:
2041:
1982:
1929:
1876:
1833:
1790:
1737:
1692:
1619:
1586:
1572:
1518:
1473:
1434:
1397:
1348:
1307:
1212:
1204:
585:
488:
process, and so AGN jets are a second potential source of any observed continuum radiation.
439:
423:
354:
225:
156:
63:
1720:
Greenstein, J. L.; Matthews, T. A. (1963). "Red-Shift of the Unusual Radio Source: 3C 48".
1031:
5628:
5578:
5553:
5349:
5193:
5100:
5066:
4978:
4530:
4453:
4145:
4118:
4089:
4041:
3887:
3612:
3452:; Krongold Y.; Goudis C. (2006). "Local and Large-Scale Environment of Seyfert Galaxies".
3449:
3392:
1536:
501:
335:
326:
299:
232:
201:
1402:
1377:
1187:
Fath, Edward A. (1909). "The spectra of some spiral nebulae and globular star clusters".
500:(ADAF). In this type of accretion, which is important for accretion rates well below the
5528:
3819:
3755:
3695:
3638:
3581:
3528:
3475:
3418:
3298:
3243:
3186:
3133:
3018:
2965:
2912:
2859:
2812:
2765:
2710:
2661:
2618:
2575:
2532:
2495:
2452:
2407:
2299:
2272:
2235:
2194:
2145:
2037:
1978:
1925:
1872:
1829:
1786:
1733:
1688:
1514:
1469:
1430:
1393:
1344:
1303:
1272:
1245:
1208:
1200:
1137: – Relationship between the mass of a galaxy bulge and the mass of the supermassive
5543:
5295:
5234:
5078:
4752:
4394:
4227:
4130:
4125:
4079:
4022:
3163:
Laor, A. (2003). "On the Nature of Low-Luminosity Narrow-Line Active Galactic Nuclei".
1158: – Beam of ionized matter flowing along the axis of a rotating astronomical object
767:
408:
404:
398:
322:
197:
169:
105:
3306:
3141:
2920:
1955:
Narayan, R.; Yi, I. (1994). "Advection-Dominated Accretion: A Self-Similar Solution".
5717:
5603:
5523:
5051:
5046:
4550:
4416:
4379:
4150:
4113:
4101:
3953:
3948:
3851:
3781:
3597:
3589:
3544:
3491:
3202:
3095:
2928:
2719:
2684:
2416:
2381:
2070:
1610:
1554:
1362:
1259:
Slipher, Vesto (1917). "The spectrum and velocity of the nebula N.G.C. 1068 (M 77)".
914:
620:
419:
303:
272:
271:
led to further progress in discovery of new radio sources as well as identifying the
260:
193:
3713:
3654:
3434:
3261:
3042:
2781:
2685:"High-redshift Faranoff-Riley type II radio galaxies: X-ray properties of the cores"
2591:
2548:
2425:
2055:
1941:
1802:
5695:
5558:
5432:
5400:
5008:
4927:
4545:
4448:
4389:
4374:
4280:
4205:
4000:
3990:
3314:
3149:
2981:
2875:
2728:
2634:
2363:
2163:
1994:
1888:
1845:
1749:
1706:
1487:
1149:
988:
630:
252:
205:
189:
67:
3087:
2261:
The First Stromlo Symposium: The Physics of Active Galaxies. ASP Conference Series
5598:
3796:
environments of accreting massive black holes are shaped by radiative feedback".
3615:; Marziani, D. (2002). "The Circumgalactic Environment of Bright IRAS Galaxies".
2355:
5548:
5502:
5405:
5280:
5219:
4944:
4852:
4646:
4463:
4353:
4343:
4140:
4106:
4046:
3926:
1378:"The occurrence of λ3727 [O II] in the spectra of extragalactic nebulae"
513:
481:
244:
113:
51:
3764:
3729:
3704:
3669:
2474:
Antonucci, R. (1993). "Unified Models for Active Galactic Nuclei and Quasars".
1604:
Petrosian, Artashes R.; Harutyunian, Haik A.; Mickaelian, Areg M. (June 1997).
476:
can be used to study the synchrotron radiation they emit at resolutions of sub-
17:
5588:
5518:
5487:
5462:
5415:
5410:
5395:
5061:
4998:
4988:
4889:
4725:
4348:
4285:
2821:
2796:
2439:
Grandi, S. A.; Osterbrock, D. E. (1978). "Optical spectra of radio galaxies".
2244:
2219:
2096:
2046:
2009:
951:
624:
469:
457:
453:
370:
240:
185:
177:
46:, with characteristics indicating that this luminosity is not produced by the
3835:
3773:
2104:
1217:
204:
noted the presence of unusual emission lines in some galaxy nuclei. In 1943,
5623:
5270:
5173:
4961:
4956:
4358:
3252:
3217:
2154:
536:
307:
192:(published in 1918). Further spectroscopic studies by astronomers including
98:
75:
55:
3843:
3034:
1541:"Obituary: Victor Amazaspovich Ambartsumian, 1912 [i.e. 1908]–1996"
1454:"Positions of Three Discrete Sources of Galactic Radio-Frequency Radiation"
403:
In the standard model of AGN, cold material close to a black hole forms an
3868:
2010:"The accretion luminosity of a massive black hole in an elliptical galaxy"
5533:
5492:
5390:
3629:
3466:
3409:
3177:
3009:
2956:
2850:
2797:"Is it possible to turn an elliptical radio galaxy into a BL Lac object?"
2756:
2701:
2523:
2398:
2338:
2028:
1969:
1916:
1777:
1117:
291:
248:
221:
217:
213:
209:
173:
59:
3827:
1859:
Lynden-Bell, Donald (1969). "Galactic Nuclei as Collapsed Old Quasars".
1816:
Lynden-Bell, Donald (1969). "Galactic Nuclei as Collapsed Old Quasars".
1152: – Type of active galaxy that is very luminous at radio wavelengths
82:. The non-stellar radiation from an AGN is theorized to result from the
5573:
2509:
Urry, P.; Padovani, Paolo (1995). "Unified schemes for radioloud AGN".
365:
Since the late 1960s it has been argued that an AGN must be powered by
3536:
1741:
1697:
1672:
1116:
For a long time, active galaxies held all the records for the highest-
5593:
5583:
5563:
5285:
4884:
4874:
4195:
4180:
3910:
2626:
2583:
1880:
1837:
1624:
1605:
1478:
1453:
1143:
877:
840:
616:
592:
477:
415:
295:
276:
148:
128:
124:
39:
3275:
Elitzur, M. (2012). "On the Unification of Active Galactic Nuclei".
1763:
Shields, G. A. (1999). "A Brief History of Active Galactic Nuclei".
1146: – Active galactic nucleus containing a supermassive black hole
5690:
3810:
3746:
3686:
3646:
3483:
3426:
3194:
3026:
2973:
2867:
2773:
2669:
2540:
2460:
2307:
2203:
2178:
2136:
2087:
1986:
1933:
1794:
1522:
1438:
1353:
1328:
1312:
1287:
444:
93:
Active galactic nuclei are the most luminous persistent sources of
27:
Compact region at a galaxy's center with abnormally high luminosity
4268:
4263:
4258:
4215:
3572:
3519:
3342:
3289:
3234:
3124:
3070:
2903:
1288:"The Emission Spectrum of the Extra-Galactic Nebula N. G. C. 1275"
1050:
1030:
730:
443:
311:
142:
71:
607:
There are several subtypes of radio-loud active galactic nuclei.
1644:
Komberg, B. V. (1992). "Quasars and Active Galactic Nuclei". In
47:
4698:
3883:
1417:
Seyfert, Carl K. (1943). "Nuclear Emission in Spiral Nebulae".
50:. Such excess, non-stellar emissions have been observed in the
4694:
3218:"Evolution of broad-line emission from active galactic nuclei"
422:. A large fraction of the AGN's radiation may be obscured by
341:
Today, AGN are a major topic of astrophysical research, both
180:
by Edward Fath (published in 1909), and the discovery of the
3879:
1092:
of selection biases due to anisotropic selection criteria.
321:
was suggested as the source of quasars' power in papers by
302:, published in 1963. Schmidt noted that if this object was
3804:(7673). Springer Science and Business Media LLC: 488–491.
2382:"The X-ray nuclei of intermediate-redshift radio sources"
512:
AGN are a candidate source of high and ultra-high energy
464:
contrasts with the yellow starlight from the host galaxy.
2380:
Hardcastle, M. J.; Evans, D. A.; Croston, J. H. (2006).
2683:
Belsole, E.; Worrall, D. M.; Hardcastle, M. J. (2006).
2511:
Publications of the Astronomical Society of the Pacific
1765:
Publications of the Astronomical Society of the Pacific
1673:"3C 273 : A Star-Like Object with Large Red-Shift"
1333:
Publications of the Astronomical Society of the Pacific
1292:
Publications of the Astronomical Society of the Pacific
411:
of hot material forms above the accretion disc and can
5667:
369:
of mass onto massive black holes (10 to 10 times the
42:
that emits a significant amount of energy across the
1139:
Pages displaying wikidata descriptions as a fallback
531:
Among the many interesting characteristics of AGNs:
5511:
5363:
5325:
5304:
5243:
5202:
5151:
5017:
4910:
4820:
4745:
4559:
4474:
4367:
4326:
4236:
4171:
4062:
3917:
1452:Bolton, J. G.; Stanley, G. J.; Slee, O. B. (1949).
2648:Barthel, P. D. (1989). "Is every quasar beamed?".
542:small emitting regions, milli-parsecs in diameter,
468:Some accretion discs produce jets of twin, highly
3222:Monthly Notices of the Royal Astronomical Society
2801:Monthly Notices of the Royal Astronomical Society
2689:Monthly Notices of the Royal Astronomical Society
2386:Monthly Notices of the Royal Astronomical Society
2224:Monthly Notices of the Royal Astronomical Society
2124:Monthly Notices of the Royal Astronomical Society
2015:Monthly Notices of the Royal Astronomical Society
1650:Astrophysics on the Threshold of the 21st Century
290:A major breakthrough was the measurement of the
78:wavebands. A galaxy hosting an AGN is called an
535:very high luminosity, visible out to very high
259:as a tidally distorted galaxy with an unusual
4710:
4536:List of the most distant astronomical objects
3895:
3216:Elitzur, M.; Ho, L. C.; Trump, J. R. (2014).
2375:
2373:
1546:Bulletin of the American Astronomical Society
224:. Active galaxies such as these are known as
8:
3448:Koulouridis, E.; Plionis M.; Chavushyan V.;
2319:
2317:
1329:"The Spectrum of the Spiral Nebula NGC 4151"
580:Low-ionization nuclear emission-line regions
3734:The Astrophysical Journal Supplement Series
3330:Astronomical and Astrophysical Transactions
2476:Annual Review of Astronomy and Astrophysics
2071:"Active galactic nuclei: what's in a name?"
1582:Complete Dictionary of Scientific Biography
5276:Magnetospheric eternally collapsing object
4717:
4703:
4695:
3902:
3888:
3880:
3809:
3763:
3745:
3703:
3685:
3628:
3571:
3518:
3465:
3408:
3341:
3288:
3251:
3233:
3176:
3123:
3069:
3008:
2955:
2902:
2849:
2820:
2755:
2718:
2700:
2522:
2415:
2397:
2337:
2243:
2202:
2153:
2135:
2086:
2045:
2027:
1968:
1915:
1776:
1696:
1623:
1477:
1401:
1352:
1311:
1216:
38:) is a compact region at the center of a
2220:"Optical spectra of 3 CR radio galaxies"
1075:Criticism of the radio-quiet unification
638:Features of different types of galaxies
636:
5674:
3740:(1). American Astronomical Society: 9.
1179:
228:in honor of Seyfert's pioneering work.
2118:Belfiore, Francesco (September 2016).
552:detectable emission across the entire
314:, even more distant at redshift 0.37.
2075:The Astronomy and Astrophysics Review
519:Centrifugal mechanism of acceleration
267:of 16,700 kilometers per second. The
7:
5652:
2218:Hine, R. G.; Longair, M. S. (1979).
5724:Astronomical classification systems
2496:10.1146/annurev.aa.31.090193.002353
2008:Fabian, A. C.; Rees, M. J. (1995).
1577:"Ambartsumian, Viktor Amazaspovich"
1164: – Largest type of black hole
498:Advection Dominated Accretion Flow
456:-long jet ejected from the active
279:(later abbreviated as "quasars").
90:at the center of its host galaxy.
25:
2183:The Astrophysical Journal Letters
474:very-long-baseline interferometry
5701:
5689:
5677:
5651:
5642:
5641:
4940:Tolman–Oppenheimer–Volkoff limit
4811:
4676:
4665:
4664:
3867:
2720:10.1111/j.1365-2966.2005.09882.x
2417:10.1111/j.1365-2966.2006.10615.x
1403:10.5479/ADS/bib/1939LicOB.19.33M
1234:Publications of Lick Observatory
5057:Innermost stable circular orbit
1209:10.5479/ADS/bib/1909LicOB.5.71F
1170: – Astrophysical technique
1112:Cosmological uses and evolution
282:Soviet Armenian astrophysicist
163:caused by the telescope optics.
5483:Timeline of black hole physics
4607:Galaxy formation and evolution
4602:Galaxy color–magnitude diagram
2179:"When Is BL Lac Not a BL Lac?"
1:
5251:Nonsingular black hole models
3397:Astrophysical Journal Letters
3277:Astrophysical Journal Letters
1606:"Victor Amazasp Ambartsumian"
527:Observational characteristics
116:, and presence or absence of
1376:Mayall, Nicholas U. (1939).
1327:Mayall, Nicholas U. (1934).
5473:Rossi X-ray Timing Explorer
5438:Hypercompact stellar system
5428:Gamma-ray burst progenitors
4489:Galaxies named after people
3307:10.1088/2041-8205/747/2/L33
3142:10.1088/0004-637X/746/2/137
3088:10.1051/0004-6361/201016409
2921:10.1088/0004-637X/730/2/121
1286:Humason, Milton L. (1932).
1261:Lowell Observatory Bulletin
492:Radiatively inefficient AGN
389:of the central black hole.
381:of the galactic bulge (the
277:quasi-stellar radio sources
5750:
5159:Black hole complementarity
5126:Bousso's holographic bound
5111:Quasi-periodic oscillation
4809:
4803:Malament–Hogarth spacetime
4622:Gravitational microlensing
4577:Galactic coordinate system
3590:10.1088/0004-637X/789/1/44
3367:Astronomy and Astrophysics
3058:Astronomy and Astrophysics
2356:10.1051/0004-6361:20021204
1027:Unification of AGN species
486:inverse-Compton scattering
437:
396:
5637:
5030:Gravitational singularity
4732:
4660:
3674:The Astrophysical Journal
3560:The Astrophysical Journal
3165:The Astrophysical Journal
3112:The Astrophysical Journal
2997:The Astrophysical Journal
2944:The Astrophysical Journal
2891:The Astrophysical Journal
2838:The Astrophysical Journal
2795:Browne, I. W. A. (1983).
2744:The Astrophysical Journal
2288:The Astrophysical Journal
2097:10.1007/s00159-017-0102-9
1904:The Astrophysical Journal
1671:Schmidt, Maarten (1963).
1503:The Astrophysical Journal
1419:The Astrophysical Journal
1382:Lick Observatory Bulletin
1189:Lick Observatory Bulletin
672:
669:
666:
660:
657:
654:
651:
645:
642:
351:electromagnetic radiation
95:electromagnetic radiation
5614:PSO J030947.49+271757.31
5539:SDSS J150243.09+111557.3
5072:Blandford–Znajek process
4587:Galactic magnetic fields
4400:Brightest cluster galaxy
4296:Luminous infrared galaxy
3765:10.3847/1538-4365/ac5b64
3705:10.3847/1538-4357/aa5d5a
554:electromagnetic spectrum
247:. Another radio source,
44:electromagnetic spectrum
4870:Active galactic nucleus
4582:Galactic habitable zone
4567:Extragalactic astronomy
4156:Supermassive black hole
4070:Active galactic nucleus
3379:1995A&A...293..683L
3352:2012A&AT...27..557A
3080:2011A&A...532A.102R
2822:10.1093/mnras/204.1.23p
2488:1993ARA&A..31..473A
2348:2002A&A...394..791C
2245:10.1093/mnras/188.1.111
2047:10.1093/mnras/277.1.L55
1162:Supermassive black hole
1044:Radio-quiet unification
413:inverse-Compton scatter
319:supermassive black hole
88:supermassive black hole
32:active galactic nucleus
5498:Tidal disruption event
5468:Supermassive dark star
5386:Black holes in fiction
5371:Outline of black holes
5004:Supermassive dark star
4923:Gravitational collapse
4334:Low surface brightness
4085:Central massive object
3874:Active galactic nuclei
1062:Radio-loud unification
1036:
561:Types of active galaxy
465:
450:Hubble Space Telescope
164:
153:Hubble Space Telescope
5734:Concepts in astronomy
5376:Black Hole Initiative
5189:Holographic principle
4612:Galaxy rotation curve
3617:Astrophysical Journal
3454:Astrophysical Journal
3253:10.1093/mnras/stt2445
2650:Astrophysical Journal
2441:Astrophysical Journal
2155:10.1093/mnras/stw1234
1573:McCutcheon, Robert A.
1168:Reverberation mapping
1034:
508:Particle acceleration
462:synchrotron radiation
447:
146:
5179:Final parsec problem
5138:Schwarzschild radius
4647:Population III stars
4642:Intergalactic travel
4592:Galactic orientation
4459:Voids and supervoids
3876:at Wikimedia Commons
1654:Taylor & Francis
962:stronger than BL Lac
547:luminosity functions
545:strong evolution of
375:Eddington luminosity
265:recessional velocity
251:, was identified by
133:relativistic beaming
99:models of the cosmos
5729:Active galaxy types
5478:Superluminal motion
5453:Population III star
5423:Gravitational waves
5381:Black hole starship
5164:Information paradox
4637:Intergalactic stars
4526:Large quasar groups
4521:Groups and clusters
4385:Groups and clusters
4244:Lyman-alpha emitter
4136:Interstellar medium
3828:10.1038/nature23906
3820:2017Natur.549..488R
3756:2022ApJS..261....9A
3696:2017ApJ...837..110V
3639:2002ApJ...572..169K
3582:2014ApJ...789...44D
3529:2014NatPh..10..417V
3476:2006ApJ...639...37K
3419:1999ApJ...513L.111D
3299:2012ApJ...747L..33E
3244:2014MNRAS.438.3340E
3187:2003ApJ...590...86L
3134:2012ApJ...746..137W
3019:2000ApJ...530L..65N
2966:2006ApJ...648L.101E
2913:2011ApJ...730..121W
2860:2001ApJ...554L..19T
2813:1983MNRAS.204P..23B
2766:2006ApJ...647..161O
2711:2006MNRAS.366..339B
2662:1989ApJ...336..606B
2619:1988Natur.331..147G
2576:1988Natur.331..149L
2533:1995PASP..107..803U
2453:1978ApJ...220..783G
2408:2006MNRAS.370.1893H
2300:1995ApJ...451...88B
2273:1994ASPC...54..201L
2236:1979MNRAS.188..111H
2195:1995ApJ...452L...5V
2146:2016MNRAS.461.3111B
2038:1995MNRAS.277L..55F
1979:1994ApJ...428L..13N
1926:2003ApJ...589L..21M
1873:1969Natur.223..690L
1830:1969Natur.223..690L
1787:1999PASP..111..661S
1734:1963Natur.197.1041G
1689:1963Natur.197.1040S
1593:on 3 December 2019.
1575:(1 November 2019).
1515:1954ApJ...119..206B
1470:1949Natur.164..101B
1431:1943ApJ....97...28S
1394:1939LicOB..19...33M
1345:1934PASP...46..134M
1304:1932PASP...44..267H
1273:1917LowOB...3...59S
1246:1918PLicO..13....9C
1201:1909LicOB...5...71F
639:
448:Image taken by the
387:sphere of influence
379:velocity dispersion
284:Viktor Ambartsumian
263:spectrum, having a
237:elliptical galaxies
231:The development of
172:from the nuclei of
5312:Optical black hole
5225:Reissner–Nordström
5184:Firewall (physics)
5089:Gravitational lens
4632:Intergalactic dust
4617:Gravitational lens
4572:Galactic astronomy
4541:Starburst galaxies
4281:blue compact dwarf
4237:Energetic galaxies
4201:BL Lacertae object
3613:Dultzin-Hacyan, D.
3393:Dultzin-Hacyan, D.
1037:
1035:Unified AGN models
637:
466:
331:Donald Lynden-Bell
165:
161:diffraction spikes
112:of the nucleus by
5665:
5664:
5458:Supermassive star
5448:Naked singularity
5443:Membrane paradigm
5169:Cosmic censorship
5143:Spaghettification
5131:Immirzi parameter
5084:Hawking radiation
5025:Astrophysical jet
4994:Supermassive star
4984:Binary black hole
4918:Stellar evolution
4860:Intermediate-mass
4692:
4691:
4652:Galaxy X (galaxy)
4627:Illustris project
4597:Galactic quadrant
4318:Wolf-Rayet galaxy
4308:Green bean galaxy
4303:Hot dust-obscured
4254:Luminous infrared
4018:Elliptical galaxy
3872:Media related to
3537:10.1038/nphys2951
3450:Dultzin-Hacyan D.
2613:(6152): 147–149.
2570:(6152): 149–151.
2326:Astron. Astrophys
1867:(5207): 690–694.
1742:10.1038/1971041a0
1698:10.1038/1971040a0
1218:2027/uc1.c2914873
1024:
1023:
695:Normal (non-AGN)
434:Relativistic jets
329:in 1964. In 1969
257:Rudolph Minkowski
16:(Redirected from
5741:
5706:
5705:
5704:
5694:
5693:
5682:
5681:
5680:
5673:
5655:
5654:
5645:
5644:
5317:Sonic black hole
5266:Dark-energy star
5121:Bekenstein bound
5106:M–sigma relation
5035:Ring singularity
4815:
4719:
4712:
4705:
4696:
4680:
4668:
4667:
4313:Hanny's Voorwerp
4223:Relativistic jet
4097:Dark matter halo
3904:
3897:
3890:
3881:
3871:
3856:
3855:
3813:
3792:
3786:
3785:
3767:
3749:
3724:
3718:
3717:
3707:
3689:
3665:
3659:
3658:
3632:
3630:astro-ph/0202412
3608:
3602:
3601:
3575:
3555:
3549:
3548:
3522:
3502:
3496:
3495:
3469:
3467:astro-ph/0509843
3445:
3439:
3438:
3412:
3410:astro-ph/9901227
3403:(2): L111–L114.
3389:
3383:
3382:
3362:
3356:
3355:
3345:
3325:
3319:
3318:
3292:
3272:
3266:
3265:
3255:
3237:
3228:(4): 3340–3351.
3213:
3207:
3206:
3180:
3178:astro-ph/0302541
3160:
3154:
3153:
3127:
3106:
3100:
3099:
3073:
3053:
3047:
3046:
3012:
3010:astro-ph/9912524
3003:(2): L101–L104.
2992:
2986:
2985:
2959:
2957:astro-ph/0605686
2950:(2): L101–L104.
2939:
2933:
2932:
2906:
2886:
2880:
2879:
2853:
2851:astro-ph/0105462
2833:
2827:
2826:
2824:
2792:
2786:
2785:
2759:
2757:astro-ph/0601485
2739:
2733:
2732:
2722:
2704:
2702:astro-ph/0511606
2680:
2674:
2673:
2645:
2639:
2638:
2627:10.1038/331147a0
2602:
2596:
2595:
2584:10.1038/331149a0
2559:
2553:
2552:
2526:
2524:astro-ph/9506063
2506:
2500:
2499:
2471:
2465:
2464:
2436:
2430:
2429:
2419:
2401:
2399:astro-ph/0603090
2392:(4): 1893–1904.
2377:
2368:
2367:
2341:
2339:astro-ph/0207654
2321:
2312:
2311:
2283:
2277:
2276:
2256:
2250:
2249:
2247:
2215:
2209:
2208:
2206:
2174:
2168:
2167:
2157:
2139:
2115:
2109:
2108:
2090:
2066:
2060:
2059:
2049:
2031:
2029:astro-ph/9509096
2005:
1999:
1998:
1972:
1970:astro-ph/9403052
1952:
1946:
1945:
1919:
1917:astro-ph/0304274
1899:
1893:
1892:
1881:10.1038/223690a0
1856:
1850:
1849:
1838:10.1038/223690a0
1813:
1807:
1806:
1780:
1778:astro-ph/9903401
1760:
1754:
1753:
1717:
1711:
1710:
1700:
1668:
1662:
1661:
1646:Kardashev, N. S.
1641:
1635:
1629:
1627:
1625:10.1063/1.881754
1601:
1595:
1594:
1589:. Archived from
1587:Encyclopedia.com
1569:
1563:
1562:
1557:. Archived from
1537:Israelian, Garik
1533:
1527:
1526:
1498:
1492:
1491:
1481:
1479:10.1038/164101b0
1449:
1443:
1442:
1414:
1408:
1407:
1405:
1373:
1367:
1366:
1356:
1324:
1318:
1317:
1315:
1283:
1277:
1276:
1256:
1250:
1249:
1229:
1223:
1222:
1220:
1184:
1156:Relativistic jet
1140:
1135:M–sigma relation
640:
586:Seyfert galaxies
440:Relativistic jet
424:interstellar gas
383:M–sigma relation
355:galaxy evolution
226:Seyfert galaxies
157:relativistic jet
151:observed by the
108:, the degree of
21:
5749:
5748:
5744:
5743:
5742:
5740:
5739:
5738:
5714:
5713:
5712:
5702:
5700:
5688:
5678:
5676:
5668:
5666:
5661:
5633:
5609:ULAS J1342+0928
5569:SDSS J0849+1114
5554:Phoenix Cluster
5507:
5359:
5321:
5300:
5239:
5198:
5194:No-hair theorem
5147:
5101:Bondi accretion
5067:Penrose process
5013:
4979:Gamma-ray burst
4906:
4816:
4807:
4793:Direct collapse
4741:
4728:
4723:
4693:
4688:
4656:
4555:
4470:
4363:
4322:
4232:
4167:
4146:Galaxy filament
4090:Galactic Center
4058:
3913:
3908:
3864:
3859:
3794:
3793:
3789:
3726:
3725:
3721:
3667:
3666:
3662:
3610:
3609:
3605:
3557:
3556:
3552:
3504:
3503:
3499:
3447:
3446:
3442:
3391:
3390:
3386:
3364:
3363:
3359:
3327:
3326:
3322:
3274:
3273:
3269:
3215:
3214:
3210:
3162:
3161:
3157:
3108:
3107:
3103:
3055:
3054:
3050:
2994:
2993:
2989:
2941:
2940:
2936:
2888:
2887:
2883:
2835:
2834:
2830:
2794:
2793:
2789:
2741:
2740:
2736:
2682:
2681:
2677:
2647:
2646:
2642:
2604:
2603:
2599:
2561:
2560:
2556:
2508:
2507:
2503:
2473:
2472:
2468:
2447:(Part 1): 783.
2438:
2437:
2433:
2379:
2378:
2371:
2323:
2322:
2315:
2285:
2284:
2280:
2258:
2257:
2253:
2217:
2216:
2212:
2176:
2175:
2171:
2117:
2116:
2112:
2068:
2067:
2063:
2007:
2006:
2002:
1954:
1953:
1949:
1901:
1900:
1896:
1858:
1857:
1853:
1815:
1814:
1810:
1762:
1761:
1757:
1719:
1718:
1714:
1670:
1669:
1665:
1643:
1642:
1638:
1603:
1602:
1598:
1571:
1570:
1566:
1535:
1534:
1530:
1500:
1499:
1495:
1451:
1450:
1446:
1416:
1415:
1411:
1375:
1374:
1370:
1326:
1325:
1321:
1285:
1284:
1280:
1258:
1257:
1253:
1231:
1230:
1226:
1186:
1185:
1181:
1177:
1138:
1131:
1114:
1077:
1064:
1046:
1029:
652:Emission lines
605:
576:
574:Radio-quiet AGN
563:
529:
510:
502:Eddington limit
494:
442:
436:
401:
395:
363:
336:X-ray astronomy
327:Yakov Zeldovich
300:Maarten Schmidt
269:3C radio survey
233:radio astronomy
202:Nicholas Mayall
141:
86:of matter by a
28:
23:
22:
18:Galactic nuclei
15:
12:
11:
5:
5747:
5745:
5737:
5736:
5731:
5726:
5716:
5715:
5711:
5710:
5698:
5686:
5663:
5662:
5660:
5659:
5649:
5638:
5635:
5634:
5632:
5631:
5629:Swift J1644+57
5626:
5621:
5616:
5611:
5606:
5601:
5596:
5591:
5586:
5581:
5579:MS 0735.6+7421
5576:
5571:
5566:
5561:
5556:
5551:
5546:
5544:Sagittarius A*
5541:
5536:
5531:
5526:
5521:
5515:
5513:
5509:
5508:
5506:
5505:
5500:
5495:
5490:
5485:
5480:
5475:
5470:
5465:
5460:
5455:
5450:
5445:
5440:
5435:
5430:
5425:
5420:
5419:
5418:
5413:
5403:
5398:
5393:
5388:
5383:
5378:
5373:
5367:
5365:
5361:
5360:
5358:
5357:
5352:
5347:
5342:
5337:
5331:
5329:
5323:
5322:
5320:
5319:
5314:
5308:
5306:
5302:
5301:
5299:
5298:
5293:
5288:
5283:
5278:
5273:
5268:
5263:
5258:
5253:
5247:
5245:
5241:
5240:
5238:
5237:
5232:
5227:
5222:
5217:
5206:
5204:
5200:
5199:
5197:
5196:
5191:
5186:
5181:
5176:
5171:
5166:
5161:
5155:
5153:
5149:
5148:
5146:
5145:
5140:
5135:
5134:
5133:
5123:
5118:
5116:Thermodynamics
5113:
5108:
5103:
5098:
5097:
5096:
5086:
5081:
5079:Accretion disk
5076:
5075:
5074:
5069:
5059:
5054:
5049:
5044:
5043:
5042:
5037:
5027:
5021:
5019:
5015:
5014:
5012:
5011:
5006:
5001:
4996:
4991:
4986:
4981:
4976:
4975:
4974:
4969:
4964:
4954:
4953:
4952:
4942:
4937:
4936:
4935:
4925:
4920:
4914:
4912:
4908:
4907:
4905:
4904:
4903:
4902:
4897:
4892:
4887:
4882:
4877:
4872:
4862:
4857:
4856:
4855:
4845:
4844:
4843:
4840:
4835:
4824:
4822:
4818:
4817:
4810:
4808:
4806:
4805:
4800:
4795:
4790:
4785:
4780:
4775:
4770:
4765:
4760:
4755:
4753:BTZ black hole
4749:
4747:
4743:
4742:
4740:
4739:
4733:
4730:
4729:
4724:
4722:
4721:
4714:
4707:
4699:
4690:
4689:
4687:
4686:
4674:
4661:
4658:
4657:
4655:
4654:
4649:
4644:
4639:
4634:
4629:
4624:
4619:
4614:
4609:
4604:
4599:
4594:
4589:
4584:
4579:
4574:
4569:
4563:
4561:
4557:
4556:
4554:
4553:
4548:
4543:
4538:
4533:
4528:
4523:
4518:
4517:
4516:
4511:
4506:
4501:
4496:
4491:
4480:
4478:
4472:
4471:
4469:
4468:
4467:
4466:
4456:
4451:
4446:
4444:Stellar stream
4441:
4436:
4431:
4430:
4429:
4424:
4419:
4409:
4408:
4407:
4402:
4397:
4392:
4382:
4377:
4371:
4369:
4365:
4364:
4362:
4361:
4356:
4351:
4346:
4341:
4336:
4330:
4328:
4324:
4323:
4321:
4320:
4315:
4310:
4305:
4300:
4299:
4298:
4293:
4288:
4283:
4273:
4272:
4271:
4266:
4261:
4251:
4246:
4240:
4238:
4234:
4233:
4231:
4230:
4225:
4220:
4219:
4218:
4213:
4203:
4198:
4193:
4188:
4183:
4177:
4175:
4169:
4168:
4166:
4165:
4164:
4163:
4153:
4148:
4143:
4138:
4133:
4131:Galactic ridge
4128:
4126:Galactic plane
4123:
4122:
4121:
4111:
4110:
4109:
4099:
4094:
4093:
4092:
4082:
4077:
4072:
4066:
4064:
4060:
4059:
4057:
4056:
4055:
4054:
4044:
4039:
4038:
4037:
4027:
4026:
4025:
4015:
4014:
4013:
4008:
4003:
3998:
3988:
3987:
3986:
3981:
3976:
3971:
3966:
3961:
3956:
3946:
3945:
3944:
3939:
3929:
3923:
3921:
3915:
3914:
3909:
3907:
3906:
3899:
3892:
3884:
3878:
3877:
3863:
3862:External links
3860:
3858:
3857:
3787:
3719:
3660:
3647:10.1086/340299
3623:(1): 169–177.
3611:Krongold, Y.;
3603:
3550:
3513:(6): 417–420.
3507:Nature Physics
3497:
3484:10.1086/498421
3440:
3427:10.1086/311925
3384:
3357:
3320:
3283:(2): L33–L35.
3267:
3208:
3195:10.1086/375008
3155:
3118:(2): 137–165.
3101:
3048:
3027:10.1086/312491
2987:
2974:10.1086/508158
2934:
2897:(2): 121–130.
2881:
2868:10.1086/320926
2844:(1): L19–L23.
2828:
2787:
2774:10.1086/505337
2750:(1): 161–171.
2734:
2695:(1): 339–352.
2675:
2670:10.1086/167038
2640:
2597:
2554:
2541:10.1086/133630
2501:
2482:(1): 473–521.
2466:
2461:10.1086/155966
2431:
2369:
2332:(3): 791–800.
2313:
2308:10.1086/176202
2278:
2251:
2210:
2204:10.1086/309716
2169:
2110:
2061:
2022:(2): L55–L58.
2000:
1987:10.1086/187381
1947:
1934:10.1086/375804
1910:(1): L21–L24.
1894:
1851:
1808:
1795:10.1086/316378
1755:
1728:(4872): 1041.
1712:
1683:(4872): 1040.
1663:
1636:
1596:
1564:
1561:on 2015-09-11.
1528:
1523:10.1086/145812
1493:
1444:
1439:10.1086/144488
1409:
1368:
1354:10.1086/124429
1319:
1313:10.1086/124242
1278:
1251:
1224:
1178:
1176:
1173:
1172:
1171:
1165:
1159:
1153:
1147:
1141:
1130:
1127:
1113:
1110:
1076:
1073:
1063:
1060:
1045:
1042:
1028:
1025:
1022:
1021:
1018:
1015:
1012:
1009:
1006:
1003:
1000:
997:
994:
991:
985:
984:
981:
978:
975:
972:
969:
966:
963:
960:
957:
954:
948:
947:
944:
941:
938:
935:
932:
929:
926:
923:
920:
917:
911:
910:
907:
904:
901:
898:
895:
892:
889:
886:
883:
880:
874:
873:
870:
867:
864:
861:
858:
855:
852:
849:
846:
843:
837:
836:
833:
830:
827:
824:
821:
818:
815:
812:
809:
806:
802:
801:
798:
795:
792:
789:
786:
783:
780:
777:
774:
771:
764:
763:
760:
757:
754:
751:
748:
745:
742:
739:
736:
733:
727:
726:
723:
720:
717:
714:
711:
708:
705:
702:
699:
696:
692:
691:
688:
685:
682:
678:
677:
671:
668:
665:
659:
656:
653:
650:
644:
635:
634:
631:Radio galaxies
628:
621:BL Lac objects
613:
604:
603:Radio-loud AGN
601:
600:
599:
596:
589:
583:
575:
572:
562:
559:
558:
557:
550:
543:
540:
528:
525:
509:
506:
493:
490:
438:Main article:
435:
432:
420:emission lines
405:accretion disc
399:Accretion disc
397:Main article:
394:
393:Accretion disc
391:
362:
359:
323:Edwin Salpeter
294:of the quasar
198:Milton Humason
170:emission lines
140:
137:
106:accretion disk
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
5746:
5735:
5732:
5730:
5727:
5725:
5722:
5721:
5719:
5709:
5699:
5697:
5692:
5687:
5685:
5675:
5671:
5658:
5650:
5648:
5640:
5639:
5636:
5630:
5627:
5625:
5622:
5620:
5617:
5615:
5612:
5610:
5607:
5605:
5604:Markarian 501
5602:
5600:
5597:
5595:
5592:
5590:
5587:
5585:
5582:
5580:
5577:
5575:
5572:
5570:
5567:
5565:
5562:
5560:
5557:
5555:
5552:
5550:
5547:
5545:
5542:
5540:
5537:
5535:
5532:
5530:
5529:XTE J1118+480
5527:
5525:
5524:XTE J1650-500
5522:
5520:
5517:
5516:
5514:
5510:
5504:
5501:
5499:
5496:
5494:
5491:
5489:
5486:
5484:
5481:
5479:
5476:
5474:
5471:
5469:
5466:
5464:
5461:
5459:
5456:
5454:
5451:
5449:
5446:
5444:
5441:
5439:
5436:
5434:
5431:
5429:
5426:
5424:
5421:
5417:
5414:
5412:
5409:
5408:
5407:
5404:
5402:
5399:
5397:
5394:
5392:
5389:
5387:
5384:
5382:
5379:
5377:
5374:
5372:
5369:
5368:
5366:
5362:
5356:
5353:
5351:
5348:
5346:
5343:
5341:
5338:
5336:
5333:
5332:
5330:
5328:
5324:
5318:
5315:
5313:
5310:
5309:
5307:
5303:
5297:
5294:
5292:
5289:
5287:
5284:
5282:
5279:
5277:
5274:
5272:
5269:
5267:
5264:
5262:
5259:
5257:
5254:
5252:
5249:
5248:
5246:
5242:
5236:
5233:
5231:
5228:
5226:
5223:
5221:
5218:
5215:
5211:
5210:Schwarzschild
5208:
5207:
5205:
5201:
5195:
5192:
5190:
5187:
5185:
5182:
5180:
5177:
5175:
5172:
5170:
5167:
5165:
5162:
5160:
5157:
5156:
5154:
5150:
5144:
5141:
5139:
5136:
5132:
5129:
5128:
5127:
5124:
5122:
5119:
5117:
5114:
5112:
5109:
5107:
5104:
5102:
5099:
5095:
5092:
5091:
5090:
5087:
5085:
5082:
5080:
5077:
5073:
5070:
5068:
5065:
5064:
5063:
5060:
5058:
5055:
5053:
5052:Photon sphere
5050:
5048:
5047:Event horizon
5045:
5041:
5038:
5036:
5033:
5032:
5031:
5028:
5026:
5023:
5022:
5020:
5016:
5010:
5007:
5005:
5002:
5000:
4997:
4995:
4992:
4990:
4987:
4985:
4982:
4980:
4977:
4973:
4972:Related links
4970:
4968:
4965:
4963:
4960:
4959:
4958:
4955:
4951:
4950:Related links
4948:
4947:
4946:
4943:
4941:
4938:
4934:
4933:Related links
4931:
4930:
4929:
4926:
4924:
4921:
4919:
4916:
4915:
4913:
4909:
4901:
4898:
4896:
4893:
4891:
4888:
4886:
4883:
4881:
4878:
4876:
4873:
4871:
4868:
4867:
4866:
4863:
4861:
4858:
4854:
4851:
4850:
4849:
4846:
4841:
4839:
4836:
4834:
4831:
4830:
4829:
4826:
4825:
4823:
4819:
4814:
4804:
4801:
4799:
4796:
4794:
4791:
4789:
4786:
4784:
4781:
4779:
4776:
4774:
4771:
4769:
4766:
4764:
4761:
4759:
4758:Schwarzschild
4756:
4754:
4751:
4750:
4748:
4744:
4738:
4735:
4734:
4731:
4727:
4720:
4715:
4713:
4708:
4706:
4701:
4700:
4697:
4685:
4684:
4679:
4675:
4673:
4672:
4663:
4662:
4659:
4653:
4650:
4648:
4645:
4643:
4640:
4638:
4635:
4633:
4630:
4628:
4625:
4623:
4620:
4618:
4615:
4613:
4610:
4608:
4605:
4603:
4600:
4598:
4595:
4593:
4590:
4588:
4585:
4583:
4580:
4578:
4575:
4573:
4570:
4568:
4565:
4564:
4562:
4558:
4552:
4549:
4547:
4546:Superclusters
4544:
4542:
4539:
4537:
4534:
4532:
4529:
4527:
4524:
4522:
4519:
4515:
4512:
4510:
4507:
4505:
4502:
4500:
4497:
4495:
4492:
4490:
4487:
4486:
4485:
4482:
4481:
4479:
4477:
4473:
4465:
4462:
4461:
4460:
4457:
4455:
4452:
4450:
4449:Superclusters
4447:
4445:
4442:
4440:
4437:
4435:
4432:
4428:
4425:
4423:
4420:
4418:
4415:
4414:
4413:
4410:
4406:
4403:
4401:
4398:
4396:
4393:
4391:
4388:
4387:
4386:
4383:
4381:
4380:Galactic tide
4378:
4376:
4373:
4372:
4370:
4366:
4360:
4357:
4355:
4352:
4350:
4347:
4345:
4342:
4340:
4339:Ultra diffuse
4337:
4335:
4332:
4331:
4329:
4325:
4319:
4316:
4314:
4311:
4309:
4306:
4304:
4301:
4297:
4294:
4292:
4289:
4287:
4284:
4282:
4279:
4278:
4277:
4274:
4270:
4267:
4265:
4262:
4260:
4257:
4256:
4255:
4252:
4250:
4247:
4245:
4242:
4241:
4239:
4235:
4229:
4226:
4224:
4221:
4217:
4214:
4212:
4209:
4208:
4207:
4204:
4202:
4199:
4197:
4194:
4192:
4189:
4187:
4184:
4182:
4179:
4178:
4176:
4174:
4173:Active nuclei
4170:
4162:
4159:
4158:
4157:
4154:
4152:
4149:
4147:
4144:
4142:
4139:
4137:
4134:
4132:
4129:
4127:
4124:
4120:
4117:
4116:
4115:
4112:
4108:
4105:
4104:
4103:
4100:
4098:
4095:
4091:
4088:
4087:
4086:
4083:
4081:
4078:
4076:
4073:
4071:
4068:
4067:
4065:
4061:
4053:
4050:
4049:
4048:
4045:
4043:
4040:
4036:
4033:
4032:
4031:
4028:
4024:
4021:
4020:
4019:
4016:
4012:
4009:
4007:
4004:
4002:
3999:
3997:
3994:
3993:
3992:
3989:
3985:
3982:
3980:
3977:
3975:
3972:
3970:
3967:
3965:
3962:
3960:
3957:
3955:
3952:
3951:
3950:
3947:
3943:
3940:
3938:
3935:
3934:
3933:
3930:
3928:
3925:
3924:
3922:
3920:
3916:
3912:
3905:
3900:
3898:
3893:
3891:
3886:
3885:
3882:
3875:
3870:
3866:
3865:
3861:
3853:
3849:
3845:
3841:
3837:
3833:
3829:
3825:
3821:
3817:
3812:
3807:
3803:
3799:
3791:
3788:
3783:
3779:
3775:
3771:
3766:
3761:
3757:
3753:
3748:
3743:
3739:
3735:
3731:
3723:
3720:
3715:
3711:
3706:
3701:
3697:
3693:
3688:
3683:
3679:
3675:
3671:
3664:
3661:
3656:
3652:
3648:
3644:
3640:
3636:
3631:
3626:
3622:
3618:
3614:
3607:
3604:
3599:
3595:
3591:
3587:
3583:
3579:
3574:
3569:
3565:
3561:
3554:
3551:
3546:
3542:
3538:
3534:
3530:
3526:
3521:
3516:
3512:
3508:
3501:
3498:
3493:
3489:
3485:
3481:
3477:
3473:
3468:
3463:
3459:
3455:
3451:
3444:
3441:
3436:
3432:
3428:
3424:
3420:
3416:
3411:
3406:
3402:
3398:
3394:
3388:
3385:
3380:
3376:
3372:
3368:
3361:
3358:
3353:
3349:
3344:
3339:
3335:
3331:
3324:
3321:
3316:
3312:
3308:
3304:
3300:
3296:
3291:
3286:
3282:
3278:
3271:
3268:
3263:
3259:
3254:
3249:
3245:
3241:
3236:
3231:
3227:
3223:
3219:
3212:
3209:
3204:
3200:
3196:
3192:
3188:
3184:
3179:
3174:
3170:
3166:
3159:
3156:
3151:
3147:
3143:
3139:
3135:
3131:
3126:
3121:
3117:
3113:
3105:
3102:
3097:
3093:
3089:
3085:
3081:
3077:
3072:
3067:
3063:
3059:
3052:
3049:
3044:
3040:
3036:
3032:
3028:
3024:
3020:
3016:
3011:
3006:
3002:
2998:
2991:
2988:
2983:
2979:
2975:
2971:
2967:
2963:
2958:
2953:
2949:
2945:
2938:
2935:
2930:
2926:
2922:
2918:
2914:
2910:
2905:
2900:
2896:
2892:
2885:
2882:
2877:
2873:
2869:
2865:
2861:
2857:
2852:
2847:
2843:
2839:
2832:
2829:
2823:
2818:
2814:
2810:
2806:
2802:
2798:
2791:
2788:
2783:
2779:
2775:
2771:
2767:
2763:
2758:
2753:
2749:
2745:
2738:
2735:
2730:
2726:
2721:
2716:
2712:
2708:
2703:
2698:
2694:
2690:
2686:
2679:
2676:
2671:
2667:
2663:
2659:
2655:
2651:
2644:
2641:
2636:
2632:
2628:
2624:
2620:
2616:
2612:
2608:
2601:
2598:
2593:
2589:
2585:
2581:
2577:
2573:
2569:
2565:
2558:
2555:
2550:
2546:
2542:
2538:
2534:
2530:
2525:
2520:
2516:
2512:
2505:
2502:
2497:
2493:
2489:
2485:
2481:
2477:
2470:
2467:
2462:
2458:
2454:
2450:
2446:
2442:
2435:
2432:
2427:
2423:
2418:
2413:
2409:
2405:
2400:
2395:
2391:
2387:
2383:
2376:
2374:
2370:
2365:
2361:
2357:
2353:
2349:
2345:
2340:
2335:
2331:
2327:
2320:
2318:
2314:
2309:
2305:
2301:
2297:
2293:
2289:
2282:
2279:
2274:
2270:
2266:
2262:
2255:
2252:
2246:
2241:
2237:
2233:
2229:
2225:
2221:
2214:
2211:
2205:
2200:
2196:
2192:
2188:
2184:
2180:
2173:
2170:
2165:
2161:
2156:
2151:
2147:
2143:
2138:
2133:
2129:
2125:
2121:
2114:
2111:
2106:
2102:
2098:
2094:
2089:
2084:
2080:
2076:
2072:
2065:
2062:
2057:
2053:
2048:
2043:
2039:
2035:
2030:
2025:
2021:
2017:
2016:
2011:
2004:
2001:
1996:
1992:
1988:
1984:
1980:
1976:
1971:
1966:
1962:
1958:
1951:
1948:
1943:
1939:
1935:
1931:
1927:
1923:
1918:
1913:
1909:
1905:
1898:
1895:
1890:
1886:
1882:
1878:
1874:
1870:
1866:
1862:
1855:
1852:
1847:
1843:
1839:
1835:
1831:
1827:
1824:(5207): 690.
1823:
1819:
1812:
1809:
1804:
1800:
1796:
1792:
1788:
1784:
1779:
1774:
1770:
1766:
1759:
1756:
1751:
1747:
1743:
1739:
1735:
1731:
1727:
1723:
1716:
1713:
1708:
1704:
1699:
1694:
1690:
1686:
1682:
1678:
1674:
1667:
1664:
1659:
1655:
1651:
1647:
1640:
1637:
1633:
1626:
1621:
1617:
1613:
1612:
1611:Physics Today
1607:
1600:
1597:
1592:
1588:
1584:
1583:
1578:
1574:
1568:
1565:
1560:
1556:
1552:
1548:
1547:
1542:
1538:
1532:
1529:
1524:
1520:
1516:
1512:
1508:
1504:
1497:
1494:
1489:
1485:
1480:
1475:
1471:
1467:
1464:(4159): 101.
1463:
1459:
1455:
1448:
1445:
1440:
1436:
1432:
1428:
1424:
1420:
1413:
1410:
1404:
1399:
1395:
1391:
1387:
1383:
1379:
1372:
1369:
1364:
1360:
1355:
1350:
1346:
1342:
1338:
1334:
1330:
1323:
1320:
1314:
1309:
1305:
1301:
1297:
1293:
1289:
1282:
1279:
1274:
1270:
1266:
1262:
1255:
1252:
1247:
1243:
1239:
1235:
1228:
1225:
1219:
1214:
1210:
1206:
1202:
1198:
1194:
1190:
1183:
1180:
1174:
1169:
1166:
1163:
1160:
1157:
1154:
1151:
1148:
1145:
1142:
1136:
1133:
1132:
1128:
1126:
1122:
1119:
1111:
1109:
1105:
1101:
1097:
1093:
1089:
1085:
1081:
1074:
1072:
1068:
1061:
1059:
1055:
1052:
1043:
1041:
1033:
1026:
1019:
1016:
1013:
1010:
1007:
1004:
1001:
998:
995:
992:
990:
987:
986:
982:
979:
976:
973:
970:
967:
964:
961:
958:
955:
953:
950:
949:
945:
942:
939:
936:
933:
930:
927:
924:
921:
918:
916:
913:
912:
908:
905:
902:
899:
896:
893:
890:
887:
884:
881:
879:
876:
875:
871:
868:
865:
862:
859:
856:
853:
850:
847:
844:
842:
839:
838:
834:
831:
828:
825:
822:
819:
816:
813:
810:
807:
804:
803:
799:
796:
793:
790:
787:
784:
781:
778:
775:
772:
769:
766:
765:
761:
758:
755:
752:
749:
746:
743:
740:
737:
734:
732:
729:
728:
724:
721:
718:
715:
712:
709:
706:
703:
700:
697:
694:
693:
689:
686:
683:
680:
679:
676:
664:
649:
641:
632:
629:
626:
622:
618:
614:
610:
609:
608:
602:
597:
594:
590:
587:
584:
581:
578:
577:
573:
571:
567:
560:
555:
551:
548:
544:
541:
538:
534:
533:
532:
526:
524:
522:
520:
515:
507:
505:
503:
499:
491:
489:
487:
483:
479:
475:
471:
463:
459:
455:
451:
446:
441:
433:
431:
429:
425:
421:
417:
414:
410:
406:
400:
392:
390:
388:
384:
380:
376:
372:
368:
360:
358:
356:
352:
348:
344:
343:observational
339:
337:
332:
328:
324:
320:
315:
313:
309:
306:(outside the
305:
304:extragalactic
301:
297:
293:
288:
285:
280:
278:
274:
273:visible-light
270:
266:
262:
261:emission-line
258:
254:
250:
246:
242:
238:
234:
229:
227:
223:
219:
215:
211:
207:
203:
199:
195:
194:Vesto Slipher
191:
187:
183:
179:
175:
171:
162:
158:
154:
150:
145:
138:
136:
134:
130:
126:
121:
119:
115:
111:
107:
102:
100:
96:
91:
89:
85:
81:
80:active galaxy
77:
73:
69:
65:
61:
57:
53:
49:
45:
41:
37:
33:
19:
5559:PKS 1302-102
5433:Gravity well
5401:Compact star
5355:Microquasars
5340:Most massive
5244:Alternatives
5009:X-ray binary
4928:Neutron star
4869:
4865:Supermassive
4842:Hawking star
4783:Supermassive
4682:
4670:
4405:fossil group
4327:Low activity
4172:
4161:Ultramassive
4069:
3991:Dwarf galaxy
3974:intermediate
3969:grand design
3801:
3797:
3790:
3737:
3733:
3722:
3677:
3673:
3663:
3620:
3616:
3606:
3563:
3559:
3553:
3510:
3506:
3500:
3460:(1): 37–45.
3457:
3453:
3443:
3400:
3396:
3387:
3370:
3366:
3360:
3333:
3329:
3323:
3280:
3276:
3270:
3225:
3221:
3211:
3171:(1): 86–94.
3168:
3164:
3158:
3115:
3111:
3104:
3061:
3057:
3051:
3000:
2996:
2990:
2947:
2943:
2937:
2894:
2890:
2884:
2841:
2837:
2831:
2804:
2800:
2790:
2747:
2743:
2737:
2692:
2688:
2678:
2653:
2649:
2643:
2610:
2606:
2600:
2567:
2563:
2557:
2514:
2510:
2504:
2479:
2475:
2469:
2444:
2440:
2434:
2389:
2385:
2329:
2325:
2291:
2287:
2281:
2264:
2260:
2254:
2227:
2223:
2213:
2186:
2182:
2172:
2127:
2123:
2113:
2078:
2074:
2064:
2019:
2013:
2003:
1960:
1957:Astrophys. J
1956:
1950:
1907:
1903:
1897:
1864:
1860:
1854:
1821:
1817:
1811:
1771:(760): 661.
1768:
1764:
1758:
1725:
1721:
1715:
1680:
1676:
1666:
1649:
1639:
1615:
1609:
1599:
1591:the original
1580:
1567:
1559:the original
1550:
1544:
1531:
1506:
1502:
1496:
1461:
1457:
1447:
1422:
1418:
1412:
1385:
1381:
1371:
1339:(271): 134.
1336:
1332:
1322:
1298:(260): 267.
1295:
1291:
1281:
1264:
1260:
1254:
1237:
1233:
1227:
1192:
1188:
1182:
1150:Radio galaxy
1123:
1115:
1106:
1102:
1098:
1094:
1090:
1086:
1082:
1078:
1069:
1065:
1056:
1047:
1038:
989:Radio galaxy
674:
662:
647:
643:Galaxy type
606:
591:Radio-quiet
568:
564:
530:
516:
511:
495:
467:
402:
364:
340:
316:
289:
281:
253:Walter Baade
230:
206:Carl Seyfert
190:Heber Curtis
166:
122:
103:
92:
79:
68:ultra-violet
35:
31:
29:
5708:Outer space
5549:Centaurus A
5503:Planet Nine
5406:Exotic star
5335:Black holes
5281:Planck star
5230:Kerr–Newman
4945:White dwarf
4895:Radio-Quiet
4853:Microquasar
4726:Black holes
4464:void galaxy
4427:cannibalism
4412:Interacting
4368:Interaction
4354:Blue Nugget
4344:Dark galaxy
4249:Lyman-break
4141:Protogalaxy
4107:Disc galaxy
3064:: A102–21.
2656:: 606–611.
2517:: 803–845.
2230:: 111–130.
2130:(3): 3111.
805:Seyfert II
625:OVV quasars
514:cosmic rays
482:synchrotron
460:. The blue
347:theoretical
245:Centaurus A
110:obscuration
5718:Categories
5599:Q0906+6930
5589:Hercules A
5519:Cygnus X-1
5488:White hole
5463:Quasi-star
5416:Preon star
5411:Quark star
5396:Big Bounce
5256:Black star
5214:Derivation
5062:Ergosphere
5018:Properties
4999:Quasi-star
4989:Quark star
4900:Radio-Loud
4788:Primordial
4778:Kugelblitz
4504:Polar-ring
4349:Red nugget
4291:faint blue
4151:Spiral arm
4006:spheroidal
3996:elliptical
3979:Magellanic
3964:flocculent
3932:Lenticular
3919:Morphology
3811:1709.09651
3747:2201.05603
3687:1701.08647
3680:(2): 110.
3336:(4): 557.
2807:: 23–27P.
2189:(1): 5–8.
2137:1605.07189
2088:1707.07134
1656:. p.
1618:(6): 106.
1175:References
658:Excess of
537:red shifts
517:(see also
470:collimated
458:galaxy M87
454:light-year
452:of a 5000-
371:Solar mass
241:Messier 87
186:Messier 87
178:Messier 81
5684:Astronomy
5624:AT2018hyz
5271:Gravastar
5261:Dark star
5094:Microlens
4967:Hypernova
4962:Micronova
4957:Supernova
4911:Formation
4439:Satellite
4434:Jellyfish
4422:collision
4359:Dead disk
4276:Starburst
4191:Markarian
4063:Structure
4030:Irregular
4001:irregular
3852:205260182
3836:0028-0836
3782:245986416
3774:0067-0049
3598:118512526
3573:1309.2277
3566:(1): 44.
3545:119199124
3520:1211.0528
3492:118938514
3343:1210.2716
3290:1202.1776
3235:1312.4922
3203:118648122
3125:1202.0062
3096:119309875
3071:1101.4132
2929:119209693
2904:1101.4132
2105:0935-4956
1555:1466–1467
1363:119741164
670:Variable
612:emission.
367:accretion
308:Milky Way
84:accretion
76:gamma ray
56:microwave
5647:Category
5534:A0620-00
5493:Wormhole
5391:Big Bang
5291:Fuzzball
5174:ER = EPR
5040:Theorems
4838:Electron
4833:Extremal
4763:Rotating
4671:Category
4560:See also
4484:Galaxies
4211:X-shaped
4042:Peculiar
3984:unbarred
3942:unbarred
3911:Galaxies
3844:28959966
3714:67809219
3655:17282005
3435:15568552
3262:52024863
3043:23313718
3035:10655166
2782:15122568
2592:45906162
2549:17198955
2426:14632376
2056:18890265
1942:15911138
1803:18953602
1539:(1997).
1129:See also
1118:redshift
925:no/faint
484:and the
292:redshift
249:Cygnus A
239:such as
222:NGC 7469
218:NGC 3516
214:NGC 4151
210:NGC 1068
174:NGC 1068
60:infrared
5670:Portals
5657:Commons
5619:P172+18
5574:TON 618
5512:Notable
5364:Related
5350:Quasars
5345:Nearest
5305:Analogs
5235:Hayward
5203:Metrics
4848:Stellar
4773:Virtual
4768:Charged
4737:Outline
4531:Quasars
4499:Nearest
4494:Largest
4395:cluster
4228:Seyfert
3816:Bibcode
3752:Bibcode
3692:Bibcode
3635:Bibcode
3578:Bibcode
3525:Bibcode
3472:Bibcode
3415:Bibcode
3375:Bibcode
3373:: 683.
3348:Bibcode
3315:5037009
3295:Bibcode
3240:Bibcode
3183:Bibcode
3150:5037595
3130:Bibcode
3076:Bibcode
3015:Bibcode
2982:1972144
2962:Bibcode
2909:Bibcode
2876:2753150
2856:Bibcode
2809:Bibcode
2762:Bibcode
2729:9509179
2707:Bibcode
2658:Bibcode
2635:4347023
2615:Bibcode
2572:Bibcode
2529:Bibcode
2484:Bibcode
2449:Bibcode
2404:Bibcode
2364:4308057
2344:Bibcode
2296:Bibcode
2269:Bibcode
2267:: 201.
2232:Bibcode
2191:Bibcode
2164:3353122
2142:Bibcode
2034:Bibcode
1995:8998323
1975:Bibcode
1963:: L13.
1922:Bibcode
1889:4164497
1869:Bibcode
1846:4164497
1826:Bibcode
1783:Bibcode
1750:4193798
1730:Bibcode
1707:4186361
1685:Bibcode
1648:(ed.).
1511:Bibcode
1509:: 206.
1488:4073162
1466:Bibcode
1427:Bibcode
1390:Bibcode
1341:Bibcode
1300:Bibcode
1269:Bibcode
1242:Bibcode
1197:Bibcode
768:Seyfert
735:unknown
690:Far-IR
661:Strong
655:X-rays
648:nuclei
646:Active
617:Blazars
593:quasars
416:photons
147:Quasar
139:History
125:quasars
64:optical
5594:3C 273
5584:NeVe 1
5564:OJ 287
5286:Q star
5152:Issues
4885:Blazar
4875:Quasar
4683:Portal
4514:Spiral
4417:merger
4196:Quasar
4181:Blazar
4119:corona
4035:barred
4011:spiral
3959:barred
3954:anemic
3949:Spiral
3937:barred
3850:
3842:
3834:
3798:Nature
3780:
3772:
3712:
3653:
3596:
3543:
3490:
3433:
3313:
3260:
3201:
3148:
3094:
3041:
3033:
2980:
2927:
2874:
2780:
2727:
2633:
2607:Nature
2590:
2564:Nature
2547:
2424:
2362:
2294:: 88.
2162:
2103:
2054:
1993:
1940:
1887:
1861:Nature
1844:
1818:Nature
1801:
1748:
1722:Nature
1705:
1677:Nature
1486:
1458:Nature
1425:: 28.
1388:: 33.
1361:
1267:: 59.
1195:: 71.
1144:Quasar
915:BL Lac
878:Blazar
841:Quasar
681:Narrow
673:Radio
663:radio
478:parsec
409:corona
361:Models
296:3C 273
220:, and
200:, and
155:. The
149:3C 273
129:blazar
40:galaxy
5696:Stars
5327:Lists
4828:Micro
4798:Rogue
4746:Types
4551:Voids
4476:Lists
4454:Walls
4390:group
4375:Field
4269:ELIRG
4264:HLIRG
4259:ULIRG
4216:DRAGN
4206:Radio
4186:LINER
4080:Bulge
4052:Polar
3848:S2CID
3806:arXiv
3778:S2CID
3742:arXiv
3710:S2CID
3682:arXiv
3651:S2CID
3625:arXiv
3594:S2CID
3568:arXiv
3541:S2CID
3515:arXiv
3488:S2CID
3462:arXiv
3431:S2CID
3405:arXiv
3338:arXiv
3311:S2CID
3285:arXiv
3258:S2CID
3230:arXiv
3199:S2CID
3173:arXiv
3146:S2CID
3120:arXiv
3092:S2CID
3066:arXiv
3039:S2CID
3005:arXiv
2978:S2CID
2952:arXiv
2925:S2CID
2899:arXiv
2872:S2CID
2846:arXiv
2778:S2CID
2752:arXiv
2725:S2CID
2697:arXiv
2631:S2CID
2588:S2CID
2545:S2CID
2519:arXiv
2422:S2CID
2394:arXiv
2360:S2CID
2334:arXiv
2160:S2CID
2132:arXiv
2083:arXiv
2081:(1).
2052:S2CID
2024:arXiv
1991:S2CID
1965:arXiv
1938:S2CID
1912:arXiv
1885:S2CID
1842:S2CID
1799:S2CID
1773:arXiv
1746:S2CID
1703:S2CID
1553:(4):
1484:S2CID
1359:S2CID
1240:: 9.
1051:torus
872:some
731:LINER
684:Broad
675:loud
667:Jets
312:3C 48
72:X-ray
52:radio
48:stars
5296:Geon
5220:Kerr
4821:Size
4509:Ring
4114:Halo
4102:Disc
4047:Ring
3927:Disc
3840:PMID
3832:ISSN
3770:ISSN
3031:PMID
2101:ISSN
1020:yes
1005:some
1002:some
999:some
996:some
983:yes
946:yes
909:yes
888:some
866:some
863:some
854:some
820:some
817:some
785:some
782:some
744:weak
741:weak
738:weak
707:weak
701:weak
623:and
428:dust
426:and
345:and
325:and
255:and
243:and
176:and
127:. A
118:jets
114:dust
74:and
4890:OVV
4880:LQG
4286:pea
4075:Bar
3824:doi
3802:549
3760:doi
3738:261
3700:doi
3678:837
3643:doi
3621:572
3586:doi
3564:789
3533:doi
3480:doi
3458:639
3423:doi
3401:513
3371:293
3303:doi
3281:747
3248:doi
3226:438
3191:doi
3169:590
3138:doi
3116:746
3084:doi
3062:532
3023:doi
3001:530
2970:doi
2948:648
2917:doi
2895:730
2864:doi
2842:554
2817:doi
2805:204
2770:doi
2748:647
2715:doi
2693:366
2666:doi
2654:336
2623:doi
2611:331
2580:doi
2568:331
2537:doi
2515:107
2492:doi
2457:doi
2445:220
2412:doi
2390:370
2352:doi
2330:394
2304:doi
2292:451
2240:doi
2228:188
2199:doi
2187:452
2150:doi
2128:461
2093:doi
2042:doi
2020:277
1983:doi
1961:428
1930:doi
1908:589
1877:doi
1865:223
1834:doi
1822:223
1791:doi
1769:111
1738:doi
1726:197
1693:doi
1681:197
1658:253
1632:PDF
1620:doi
1519:doi
1507:119
1474:doi
1462:164
1435:doi
1398:doi
1349:doi
1308:doi
1213:hdl
1205:doi
1017:yes
1014:yes
1011:yes
1008:yes
993:yes
980:yes
977:yes
974:yes
968:yes
965:yes
956:yes
952:OVV
943:yes
940:yes
937:yes
931:yes
928:yes
919:yes
906:yes
903:yes
900:yes
894:yes
891:yes
882:yes
869:yes
860:yes
857:yes
851:yes
848:yes
845:yes
835:no
832:yes
826:few
823:yes
811:yes
808:yes
800:no
797:yes
791:few
788:yes
779:yes
776:yes
773:yes
762:no
725:no
619:" (
298:by
188:by
184:in
182:jet
168:of
36:AGN
30:An
5720::
4023:cD
3846:.
3838:.
3830:.
3822:.
3814:.
3800:.
3776:.
3768:.
3758:.
3750:.
3736:.
3732:.
3708:.
3698:.
3690:.
3676:.
3672:.
3649:.
3641:.
3633:.
3619:.
3592:.
3584:.
3576:.
3562:.
3539:.
3531:.
3523:.
3511:10
3509:.
3486:.
3478:.
3470:.
3456:.
3429:.
3421:.
3413:.
3399:.
3369:.
3346:.
3334:27
3332:.
3309:.
3301:.
3293:.
3279:.
3256:.
3246:.
3238:.
3224:.
3220:.
3197:.
3189:.
3181:.
3167:.
3144:.
3136:.
3128:.
3114:.
3090:.
3082:.
3074:.
3060:.
3037:.
3029:.
3021:.
3013:.
2999:.
2976:.
2968:.
2960:.
2946:.
2923:.
2915:.
2907:.
2893:.
2870:.
2862:.
2854:.
2840:.
2815:.
2803:.
2799:.
2776:.
2768:.
2760:.
2746:.
2723:.
2713:.
2705:.
2691:.
2687:.
2664:.
2652:.
2629:.
2621:.
2609:.
2586:.
2578:.
2566:.
2543:.
2535:.
2527:.
2513:.
2490:.
2480:31
2478:.
2455:.
2443:.
2420:.
2410:.
2402:.
2388:.
2384:.
2372:^
2358:.
2350:.
2342:.
2328:.
2316:^
2302:.
2290:.
2265:54
2263:.
2238:.
2226:.
2222:.
2197:.
2185:.
2181:.
2158:.
2148:.
2140:.
2126:.
2122:.
2099:.
2091:.
2079:25
2077:.
2073:.
2050:.
2040:.
2032:.
2018:.
2012:.
1989:.
1981:.
1973:.
1959:.
1936:.
1928:.
1920:.
1906:.
1883:.
1875:.
1863:.
1840:.
1832:.
1820:.
1797:.
1789:.
1781:.
1767:.
1744:.
1736:.
1724:.
1701:.
1691:.
1679:.
1675:.
1652:.
1616:50
1614:.
1608:.
1585:.
1579:.
1551:29
1549:.
1543:.
1517:.
1505:.
1482:.
1472:.
1460:.
1456:.
1433:.
1423:97
1421:.
1396:.
1386:19
1384:.
1380:.
1357:.
1347:.
1337:46
1335:.
1331:.
1306:.
1296:44
1294:.
1290:.
1263:.
1238:13
1236:.
1211:.
1203:.
1191:.
971:no
959:no
934:no
922:no
897:no
885:no
829:no
814:no
794:no
770:I
759:no
756:no
753:no
750:no
747:no
722:no
719:no
716:no
713:no
710:no
704:no
698:no
687:UV
523:.
357:.
216:,
212:,
196:,
135:.
120:.
101:.
70:,
66:,
62:,
58:,
54:,
5672::
5216:)
5212:(
4718:e
4711:t
4704:v
3903:e
3896:t
3889:v
3854:.
3826::
3818::
3808::
3784:.
3762::
3754::
3744::
3716:.
3702::
3694::
3684::
3657:.
3645::
3637::
3627::
3600:.
3588::
3580::
3570::
3547:.
3535::
3527::
3517::
3494:.
3482::
3474::
3464::
3437:.
3425::
3417::
3407::
3381:.
3377::
3354:.
3350::
3340::
3317:.
3305::
3297::
3287::
3264:.
3250::
3242::
3232::
3205:.
3193::
3185::
3175::
3152:.
3140::
3132::
3122::
3098:.
3086::
3078::
3068::
3045:.
3025::
3017::
3007::
2984:.
2972::
2964::
2954::
2931:.
2919::
2911::
2901::
2878:.
2866::
2858::
2848::
2825:.
2819::
2811::
2784:.
2772::
2764::
2754::
2731:.
2717::
2709::
2699::
2672:.
2668::
2660::
2637:.
2625::
2617::
2594:.
2582::
2574::
2551:.
2539::
2531::
2521::
2498:.
2494::
2486::
2463:.
2459::
2451::
2428:.
2414::
2406::
2396::
2366:.
2354::
2346::
2336::
2310:.
2306::
2298::
2275:.
2271::
2248:.
2242::
2234::
2207:.
2201::
2193::
2166:.
2152::
2144::
2134::
2107:.
2095::
2085::
2058:.
2044::
2036::
2026::
1997:.
1985::
1977::
1967::
1944:.
1932::
1924::
1914::
1891:.
1879::
1871::
1848:.
1836::
1828::
1805:.
1793::
1785::
1775::
1752:.
1740::
1732::
1709:.
1695::
1687::
1660:.
1634:)
1630:(
1628:.
1622::
1525:.
1521::
1513::
1490:.
1476::
1468::
1441:.
1437::
1429::
1406:.
1400::
1392::
1365:.
1351::
1343::
1316:.
1310::
1302::
1275:.
1271::
1265:3
1248:.
1244::
1221:.
1215::
1207::
1199::
1193:5
615:"
556:.
549:,
539:,
521:)
34:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.