Messier 87

Virgo A
Messier 87 Hubble WikiSky.jpg
The Messier 87 galaxy.
Observation data
Epoch J2000
Constellation Virgo
Right ascension 12h 30m 49.42338s[1]
Declination +12° 23′ 28.0439″[1]
Apparent dimension (V) 8.3 × 6.6 moa[2]
Apparent magnitude (V) 9.59[2]
Characteristics
Type E+0-1 pec, NLRG Sy[2]
Astrometry
Helio Radial velocity 1307 ± 7[2]km/s
Redshift 0.004360 ± 0.000022[2]
Galactocentric Velocity 1254 ± 7[2] km/s
Distance 55 ± 1 Mly (17 ± 0.31 Mpc)[3]
Other designations
Virgo A, Virgo X-1, NGC 4486, UGC 7654, PGC 41316, VCC 1316, Arp 152, 3C 274,[2] 3U 1228+12.[4]
Database references
SIMBAD Search M87 data
See also: Galaxy, List of galaxies

Messier 87 (also known as M87, Virgo A or NGC 4486) is a supergiant elliptical galaxy. The galaxy is the largest and brightest galaxy within the northern Virgo Cluster, located about 55 million light years away.[5] The galaxy also contains a notable active galactic nucleus that is a strong source of multiwavelength radiation, particularly radio waves.[6]

Since this is the largest giant elliptical galaxy near Earth and is one of the brightest radio sources in the sky, Messier 87 is a popular target for both amateur astronomy observations and professional astronomy study.

Contents

Observation history

In 1781, French astronomer Charles Messier published a catalogue of 103 objects that had a nebulous appearance. This list was intended to identify objects that might be confused with comets. In subsequent use, each item in the catalogue was prefixed with an 'M'. Thus, M87 was the eighty seventh member of Messier's catalogue.[7] During the 1880s, this galaxy was included in the New General Catalogue as NGC 4486. This compilation of nebulae and star clusters was assembled by the Danish-Irish astronomer John Dreyer based primarily on the observations of English astronomer John Herschel.[8]

In 1918, American astronomer Heber Curtis of Lick Observatory observed that there was no spiral structure and he noticed a "curious straight ray ... apparently connected with the nucleus by a thin line of matter." The ray appeared brightest at the inner end.[9] The following year, a supernova was observed within the nebula that reached a peak photographic magnitude of 21.5.[10][11] American astronomer Edwin Hubble categorized Messier 87 as one of the brighter globular nebulae, as it lacked any spiral structure but appeared to belong to the same family of non-galactic nebulae as spiral nebulae.[12] In 1926 he produced a new categorization of nebulae, with Messier 87 being a type of elliptical extra-galactic nebula with no apparent elongation (class E0).[13] By 1931, Hubble had identified Messier 87 as a member of the Virgo cluster, for which he gave a provision distance estimate of 1.8 million parsecs. At the time it was the only known example of an elliptical nebula for which individual stars could be resolved.[14]

In 1947, a prominent radio source was identified overlapping the location of Messier 87, and this was labeled Virgo-A.[15] This identification was confirmed by 1953, and the linear jet emerging from the core of Messier 87 was suggested as the cause. This jet extended from the core at a position angle of 260° to an angular distance of 20″ with an angular width of 2″.[6] German-American astronomer Walter Baade found that the light from this jet is plane polarized, which suggested that the energy was being generated by the acceleration of electrons moving at relativistic velocities in a magnetic field. The total energy output of these electrons was estimated as 5 × 1056 eV.[16] In 1969-70, a strong component of the radio emission was found to closely align with the optical source of the jet.[4]

The US Naval Research Laboratory group launched an Aerobee 150 on April 25, 1965. This flight discovered seven candidate X-ray sources, including the first extragalactic X-ray source, designated Virgo X-1 as the first X-ray source detected in Virgo.[17] A later Aerobee rocket launched from White Sands Missile Range on July 7, 1967, yielded further evidence that the source Virgo X-1 was the radio galaxy Messier 87.[18] Subsequent X-ray observations by the HEAO 1 and Einstein Observatory showed a complex source that included the active galactic nucleus of Messier 87.[19] However, there is little central concentration of the X-ray emission.[4]

Properties

The location of M87 (upper right) in Virgo

Messier 87 is located near the high declination border of the Virgo, next to the Coma Berenices constellation. It lies along a line between the stars Epsilon Virginis and Denebola.[20] At an apparent magnitude of 9.59, this galaxy can be readily observed using a small telescope with a 6 cm (2.4 in) aperture. Visually, the galaxy extends across an angular area of 7′.2 × 6′.8, with a bright, 45″ core.[21] The jet is magnitude 15 and it overlays the bright, central part of the galaxy, so this feature can not be seen using a small telescope. The only known visual observation of the jet was by Russian-American astronomer Otto Struve using the 254 cm (100 in) Hooker telescope.[22]

In the modified Hubble sequence galaxy morphological classification scheme of French astronomer Gérard de Vaucouleurs, Messier 87 is categorized as an E0p galaxy. The E0 indicates an elliptical galaxy that displays no flattening. That is, it appears spherical in profile.[23] A 'p' suffix indicates a peculiar galaxy that does not fit cleanly into the classification scheme. In this case the peculiarity is caused by the presence of a relativistic jet emerging from the core.[23][24] Messier 87 is considered a type-cD galaxy, which is a supergiant D class galaxy.[25][26] The latter category, first proposed by American astronomer William W. Morgan in 1958, is a galaxy that has an elliptical-like nucleus surrounded by an extensive, dustless, diffuse envelope.[27][28]

Enclosed mass
Mass
×1012 M☉		 Radius
kpc
2.4[29] 32
3.0[30] 44
6.0[31] 50

The mass of Messier 87 within a radius of 9–40 kpc from the core steadily increases roughly in proportion to r1.7, where r is the radius from the core.[30] Within a radius of 32 kpc (100 kly), the mass is (2.4 ± 0.6) × 1012 times the mass of the Sun.[29] This is double the mass of the Milky Way galaxy.[32] The total mass of Messier 87 may be 200 times that of the Milky Way.[33] However, only a fraction of this mass is in the form of stars, as Messier 87 has an estimated mass to luminosity ratio of 6.3 ± 0.8. That is, about one part in six of the galaxy's mass is in the form of stars that are radiating energy.[34] Gas is infalling into the galaxy at the rate of 2-3 solar masses per year. Most of this gas may be accreted onto the core of the galaxy.[35]

The extended stellar envelope of this galaxy reaches a radius of about 150 kpc (490 kly).[36][37] The stars in the envelope are moving in predominantly radial orbits.[38]

Beyond that distance the outer edges of the galaxy has been truncated by some mechanism. The cause may have been an earlier encounter with another galaxy.[36][37] There is some evidence of linear streams of stars to the northwest of the galaxy that may have been created by tidal stripping of orbiting galaxies, or by small satellite galaxies falling in toward Messier 87.[39]

Components

Artist's concept of a supermassive black hole and its accretion disk

At the core of this galaxy is a supermassive black hole with an estimated (6.4 ± 0.65) × 109 times the mass of the Sun and a diameter larger than the orbit of Pluto.[40] This is one of the highest masses known for a black hole.[34] Surrounding the black hole is a rotating disk of ionized gas that is oriented roughly perpendicular to the jet. This gas is moving at velocities of up to roughly 1,000 km/s.[41] Gas is accreting onto the black hole at an estimated rate equal to the mass of the Sun every ten years.[42]

The black hole in M87 is displaced from the galaxy center by a distance of about 25 pc (82 ly).[43] The displacement is in the opposite direction from the one-sided jet, and may indicate that the black hole has been accelerated by the jet.[44]

The space between the stars in the Messier 87 galaxy is filled with a diffuse interstellar medium of gas. This medium has been chemically enriched by the elements ejected from stars as they passed beyond the end of their main sequence lifetime. Carbon and nitrogen is being continually supplied by intermediate mass stars as they pass through the asymptotic giant branch. The heavier elements from oxygen to iron are primarily produced by supernovae explosions within the galaxy. About 60% of the abundance of these heavy elements was produced by core-collapse supernovae, while the remainder came from Type Ia supernovae. The distribution of these elements suggests that early enrichment was from core-collapse supernovae. However, the contribution from this source was much lower in abundance than in the Milky Way. Type Ia supernovae have provided a continuous contribution to the interstellar medium of Messier 87 throughout the history of the galaxy.[45]

Within a 4 kpc (13 kly) radius of the core, the abundance of elements other than hydrogen and helium—what astronomers term the metallicity—is about half the abundance in the Sun. Outside this radius, the abundance of metals steadily decreases with increasing distance from the core.[46] Although this is classified as an elliptical galaxy and therefore lacks the dust lanes of a spiral galaxy, optical filaments have been observed in Messier 87. These filaments have an estimated mass of about 10,000 times the mass of the Sun.[35] Surrounding the galaxy is an extended corona with hot, low density gas.[46]

Messier 87 has an abnormally large population of globular clusters. A 2006 survey out to an angular distance of 25′ from its core estimates that there are 12,000 ± 800 globulars in orbit around Messier 87, as compared to the Milky Way's 150-200.[47]

Jet

A jet of matter ejected from M87 at nearly light speed stretches 5,000 ly from the galactic core.

The jet of matter emerging from the core extends at least 5000 light-years from the nucleus of Messier 87 and is made up of matter ejected from the galaxy, most likely by a supermassive black hole. In pictures taken by the Hubble Space Telescope in 1999, the motion of Messier 87's jet was measured at four to six times the speed of light. This motion is believed by some to be a visual result of the relativistic velocity of the jet, and not true superluminal motion. However, detection of such motion supports the theory that quasars, BL Lac objects and radio galaxies may all be the same phenomenon, known as active galaxies, viewed from different perspectives.[48][49]

Observations made by Chandra X-ray Observatory indicate the presence of loops and rings in the hot X-ray emitting gas that permeate the cluster and surround Messier 87. These loops and rings are generated by pressure waves. The pressure waves are caused by variations in the rate at which material is ejected from the supermassive black hole in jets. The distribution of loops suggests that minor eruptions occur every six million years. One of the rings, caused by a major eruption, is a shock wave 85,000 light-years in diameter around the black hole. Other remarkable features observed include narrow X-ray emitting filaments up to 100,000 light-years long, and a large cavity in the hot gas caused by a major eruption 70 million years ago. The regular eruptions prevent a huge reservoir of gas from cooling and forming stars, implying that M87’s evolution may have been seriously affected, preventing it from becoming a large Spiral galaxy. The observations also imply the presence of sound waves: 56 octaves below middle C for the minor eruptions and 58 to 59 below middle C for the major eruptions.[50]

Messier 87 is also a very strong source of gamma rays, which are the most energetic rays of the electromagnetic spectrum; more than a million times as powerful as visible light. Gamma rays coming from Messier 87 have been observed since the late 1990s, but recently, using the HESS Cherenkov telescopes, scientists have measured the variations of the gamma ray flux coming from Messier 87, and found that the flux changes over a matter of days. This short period makes the immediate vicinity of the supermassive black hole in Messier 87[51] the most promising source for these gamma rays. In general, the smaller the diameter, the faster the variations, and vice versa.

A knot of matter in the jet, designated HST-1, has been tracked by the Hubble Space Telescope and the Chandra X-ray Observatory. This knot is about 65 pc (210 ly) from the core. By 2006, the X-ray intensity of this knot had increased by a factor of 50 over a four year period.[52] This has since been decaying in a variable manner.[53]

Cluster membership

A cluster of galaxies
The Virgo Cluster showing the diffuse light between the galaxies belonging to the cluster. Messier 87 is to lower left.

This supergiant elliptical galaxy is located near the center of the Virgo Cluster.[26] This cluster forms the core of the larger Virgo Supercluster, of which the Local Group, and hence the Milky Way galaxy, is an outlying member. In terms of mass, Messier 87 is a dominant member of the cluster, and hence appears to be moving very little relative to the cluster as a whole. The galaxies Messier 87 and Messier 86 appear to be moving toward each other and this may be their first encounter. Messier 87 may have encountered Messier 84 in the past.[36]

See also

References

  1. ↑ 1.0 1.1 Lambert, S. B.; Gontier, A.-M. (January 2009). "On radio source selection to define a stable celestial frame". Astronomy and Astrophysics 493 (1): 317–323. doi:10.1051/0004-6361:200810582. Bibcode: 2009A&A...493..317L. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "Results for NGC 4486". NASA/IPAC Extragalactic Database. California Institute of Technology. http://nedwww.ipac.caltech.edu/. Retrieved 2006-10-22.  Select the "By Name" cell, then enter "NGC 4486" in the "Object Name:" field of the query form.
  3. ↑ J. L. Tonry, A. Dressler, J. P. Blakeslee, E. A. Ajhar, A. B. Fletcher, G. A. Luppino, M. R. Metzger, C. B. Moore (2001). "The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances". Astrophysical Journal 546 (2): 681–693. doi:10.1086/318301. http://adsabs.harvard.edu/abs/2001ApJ...546..681T. 
  4. ↑ 4.0 4.1 4.2 Turland, B. D. (February 1975). "Observations of M87 at 5 GHz with the 5-km telescope". Monthly Notices of the Royal Astronomical Society 170: 281–294. Bibcode: 1975MNRAS.170..281T. 
  5. ↑ Binggeli, Bruno; Tammann, G. A.; Sandage, Allan (August 1987). "Studies of the Virgo cluster. VI - Morphological and kinematical structure of the Virgo cluster". Astronomical Journal 94: 251–277. doi:10.1086/114467. Bibcode: 1987AJ.....94..251B. 
  6. ↑ 6.0 6.1 Baade, W.; Minkowski, R. (1954). "On the Identification of Radio Sources". Astrophysical Journal 119: 215–231. doi:10.1086/145813. http://adsabs.harvard.edu/abs/1954ApJ...119..215B. 
  7. ↑ Basu, Baidyanath (2003). An Introduction to Astrophysics. PHI Learning Pvt. Ltd.. p. 237. ISBN 8120311213. 
  8. ↑ Dreyer, J. L. E. (1888). "A New General Catalogue of Nebulae and Clusters of Stars,being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged". Memoires of the Royal Astronomical Society 49: 1–237. Bibcode: 1888MmRAS..49....1D. 
  9. ↑ Curtis, Heber Doust (1918). "Descriptions of 762 Nebulae and Clusters Photographed with the Crossley Reflector". Publications of the Lick Observatory (University of California Press) 13: 31. http://books.google.com/?id=HYnnAAAAMAAJ. Retrieved 2010-04-26. 
  10. ↑ Hubble, E. (October 1923). "Messier 87 and Belanowsky's Nova". Publications of the Astronomical Society of the Pacific 35 (207): 261. doi:10.1086/123332. Bibcode: 1923PASP...35..261H. 
  11. ↑ Shklovskii, I. S. (August 1980). "Supernovae in Multiple Systems". Soviet Astronomy 24: 387. Bibcode: 1980SvA....24..387S. 
  12. ↑ Hubble, E. P. (October 1922). "A general study of diffuse galactic nebulae". Astrophysical Journal 56: 162–199. doi:10.1086/142698. Bibcode: 1922ApJ....56..162H. 
  13. ↑ Hubble, E. P. (December 1926). "Extragalactic nebulae". Astrophysical Journal 64: 321–369. doi:10.1086/143018. Bibcode: 1926ApJ....64..321H. 
  14. ↑ Hubble, Edwin; Humason, Milton L. (July 1931). "The Velocity-Distance Relation among Extra-Galactic". Astrophysical Journal 74: 43. doi:10.1086/143323. Bibcode: 1931ApJ....74...43H. 
  15. ↑ Stanley, G. J.; Slee, O. B. (June 1950). "Galactic Radiation at Radio Frequencies. II. The Discrete Sources". Australian Journal of Scientific Research A 3: 234. Bibcode: 1950AuSRA...3..234S. 
  16. ↑ Baldwin, J. E.; Smith, F. G. (August 1956). "Radio emission from the extragalactic nebula M87". The Observatory 76: 141–144. Bibcode: 1956Obs....76..141B. 
  17. ↑ Charles, P. A.; Seward, F. D. (1995). Exploring the X-ray universe. Cambridge, England: Press Syndicate of the University of Cambridge. p. 9. 
  18. ↑ Bradt, H.; Naranan, S.; Rappaport, S.; Spada, G. (June 1968). "Celestial Positions of X-Ray Sources in Sagittarius". Astrophysical Journal 152 (6): 1005–13. doi:10.1086/149613. Bibcode: 1968ApJ...152.1005B. 
  19. ↑ Lea, S. M.; Mushotzky, R.; Holt, S. S. (November 1982). "Einstein Observatory solid state spectrometer observations of M87 and the Virgo cluster". Astrophysical Journal, Part 1 262: 24–32. doi:10.1086/160392. Bibcode: 1982ApJ...262...24L. 
  20. ↑ Epsilon Virginis is at celestial coordinates α=13h 02m, δ=+10° 57′; Denebola is at α=11h 49m, δ=+14° 34′. The midpoint of the pair is at α=12h 16m, δ=12° 45′. Compare to the coordinates of Messier 87: α=12h 31m, δ=+12° 23′.
  21. ↑ Luginbuhl, Christian B.; Skiff, Brian A. (1998). Observing Handbook and Catalogue of Deep-Sky Objects (2 ed.). Cambridge University Press. p. 266. ISBN 0521625564. 
  22. ↑ Clark, Roger Nelson (1990). Visual astronomy of the deep sky. CUP Archive. p. 153. ISBN 0521361559. 
  23. ↑ 23.0 23.1 Park, Kyung-Suk; Chun, Mun-Suk (June 1987). "Dynamical Structure of NGC 4486". Journal of Astronomy and Space Science 4 (1): 35–45. Bibcode: 1987JASS....4...35P. 
  24. ↑ Jones, Mark H.; Lambourne, Robert J. (2004). An introduction to galaxies and cosmology. Cambridge University Press. p. 69. ISBN 0521546230. 
  25. ↑ Kundu, Arunav; Whitmore, Bradley C. (June 2001). "New Insights from HST Studies of Globular Cluster Systems. I. Colors, Distances, and Specific Frequencies of 28 Elliptical Galaxies". The Astronomical Journal 121 (6): 2950–2973. doi:10.1086/321073. Bibcode: 2001AJ....121.2950K. 
  26. ↑ 26.0 26.1 Chakrabarty, Dalia (May 2007). "Mass modelling with minimum kinematic information". Monthly Notices of the Royal Astronomical Society 377 (1): 30–40. doi:10.1111/j.1365-2966.2007.11583.x. Bibcode: 2007MNRAS.377...30C. 
  27. ↑ Oemler, A., Jr. (November 1976). "The structure of elliptical and cD galaxies". Astrophysical Journal 209: 693–709. doi:10.1086/154769. Bibcode: 1976ApJ...209..693O. 
  28. ↑ Whitmore, B. C. (May 15-17, 1989). "Effect of the Cluster Environment on Galaxies". In William R. Oegerle, Michael J. Fitchett, Laura Danly. Clusters of galaxies: proceedings of the Clusters of Galaxies Meeting, Baltimore, 1989 May 15-17, Volume 1989. Space Telescope Science Institute symposium series. 4. Baltimore: Cambridge University Press. p. 151. ISBN 0521384621. 
  29. ↑ 29.0 29.1 Wu, Xiaoan; Tremaine, Scott (2006). "Deriving the Mass Distribution of M87 from Globular Clusters". The Astrophysical Journal 643 (1): 210–221. doi:10.1086/501515. Bibcode: 2006ApJ...643..210W. 
  30. ↑ 30.0 30.1 Cohen, Judith G.; Ryzhov, Anton (September 1997). "The Dynamics of the M87 Globular Cluster System". Astrophysical Journal 486: 230. doi:10.1086/304518. Bibcode: 1997ApJ...486..230C. 
  31. ↑ Merritt, David; Tremblay, Benoit (December 1993). "The distribution of dark matter in the halo of M87". The Astronomical Journal 106 (6): 2229–2242. doi:10.1086/116796. Bibcode: 1993AJ....106.2229M. 
  32. ↑ Battaglia, G.; Helmi, A.; Morrison, H.; Harding, P.; Olszewski, E. W.; Mateo, M.; Freeman, K. C.; Norris, J.; Shectman, S. A. (2005). "The radial velocity dispersion profile of the Galactic halo: Constraining the density profile of the dark halo of the Milky Way". Monthly Notices of the Royal Astronomical Society 364: 433–442. doi:10.1111/j.1365-2966.2005.09367.x. Bibcode: 2005MNRAS.364..433B. 
  33. ↑ Leverington, David (2000). New cosmic horizons: space astronomy from the V2 to the Hubble Space Telescope. Cambridge University Press. p. 343. ISBN 0521658330. 
  34. ↑ 34.0 34.1 Gebhardt, Karl; Thomas, Jens (August 2009). "The Black Hole Mass, Stellar Mass-to-Light Ratio, and Dark Halo in M87". The Astrophysical Journal 700 (2): 1690–1701. doi:10.1088/0004-637X/700/2/1690. Bibcode: 2009ApJ...700.1690G. 
  35. ↑ 35.0 35.1 Burns, J. O.; White, R. A.; Haynes, M. P. (August 1981). "A search for neutral hydrogen in D and cD galaxies". Astronomical Journal 86: 1120–1125. doi:10.1086/112992. Bibcode: 1981AJ.....86.1120B. 
  36. ↑ 36.0 36.1 36.2 Doherty, M.; Arnaboldi, M.; Das, P.; Gerhard, O.; Aguerri, J. A. L.; Ciardullo, R.; Feldmeier, J. J.; Freeman, K. C.; Jacoby, G. H.; Murante, G. (August 2009). "The edge of the M 87 halo and the kinematics of the diffuse light in the Virgo cluster core". Astronomy and Astrophysics 502 (3): 771–786. doi:10.1051/0004-6361/200811532. Bibcode: 2009A&A...502..771D. 
  37. ↑ 37.0 37.1 Klotz, Irene (June 8, 2009). "Galaxy's Outer Halo Lopped Off". Discovery News. http://dsc.discovery.com/news/2009/06/08/galaxy-messier-star.html. Retrieved 2010-04-25. 
  38. ↑ Merritt, D.; Oh, S.-P (April 1997). "The Stellar Dynamics of M87". The Astronomical Journal 113: 1279–1285. doi:10.1086/118341. Bibcode: 1997AJ....113.1279M. http://adsabs.harvard.edu/abs/1997AJ....113.1279M. 
  39. ↑ Janowiecki, Steven; et al. (April 22, 2010). "Diffuse Tidal Structures in the Halos of Virgo Ellipticals". arXiv. http://arxiv.org/abs/1004.1473v1. Retrieved 2010-04-28. 
  40. ↑ Junor, W.; Biretta, J.; Livio, M. (2010). "M87 jet formation region". National Radio Astronomy Observatory. http://images.nrao.edu/56. Retrieved 2010-04-30. 
  41. ↑ Macchetto, F.; Marconi, A.; Axon, D. J.; Capetti, A.; Sparks, W.; Crane, P. (November 1997). "The Supermassive Black Hole of M87 and the Kinematics of Its Associated Gaseous Disk". Astrophysical Journal 489: 579. doi:10.1086/304823. Bibcode: 1997ApJ...489..579M. 
  42. ↑ Di Matteo, Tiziana; Allen, Steven W.; Fabian, Andrew C.; Wilson, Andrew S.; Young, Andrew J. (January 2003). "Accretion onto the Supermassive Black Hole in M87". The Astrophysical Journal 582 (1): 133–140. doi:10.1086/344504. Bibcode: 2003ApJ...582..133D. 
  43. ↑ Batcheldor, D.; Robinson, A.; Axon, A. J.; Perlman, E. S.; Merritt, D. (2010). "A Displaced Supermassive Black Hole in M87". The Astrophysical Journal Letters. http://arxiv.org/abs/1005.2173. Retrieved 2010-05-20. 
  44. ↑ "Black hole shoved aside, along with 'central' dogma". Science News. http://www.sciencenews.org/view/generic/id/59656/title/Black_hole_shoved_aside,_along_with_central_dogma. Retrieved 2010-05-29. 
  45. ↑ Werner, N.; Böhringer, H.; Kaastra, J. S.; de Plaa, J.; Simionescu, A.; Vink, J. (November 2006). "XMM-Newton high-resolution spectroscopy reveals the chemical evolution of M 87". Astronomy and Astrophysics 459 (2): 353–360. doi:10.1051/0004-6361:20065678. Bibcode: 2006A&A...459..353W. 
  46. ↑ 46.0 46.1 Harris, William E.; Harris, Gretchen L. H.; McLaughlin, Dean E. (May 1998). "M87, Globular Clusters, and Galactic Winds: Issues in Giant Galaxy Formation". The Astronomical Journal 115 (5): 1801–1822. doi:10.1086/300322. Bibcode: 1998AJ....115.1801H.  The authors give a metallicity of:
    \begin{smallmatrix}\left[\frac{Fe}{H}\right]\ =\ -0.3\end{smallmatrix}
    within a 3 kpc radius of the galactic core.
  47. ↑ Tamura, Naoyuki; Sharples, Ray M.; Arimoto, Nobuo; Onodera, Masato; Ohta, Kouji; Yamada, Yoshihiko (2006). "A Subaru/Suprime-Cam wide-field survey of globular cluster populations around M87 - I. Observation, data analysis and luminosity function". Monthly Notices of the Royal Astronomical Society 373 (2): 588–600. Bibcode: 2006MNRAS.373..588T. 
  48. ↑ Biretta, J. A.; Sparks, W. B.; Macchetto, F. (August 1999). "Hubble Space Telescope Observations of Superluminal Motion in the M87 Jet". The Astrophysical Journal 520 (2): 621–626. doi:10.1086/307499. Bibcode: 1999ApJ...520..621B. 
  49. ↑ John Biretta (1999-01-06). "Hubble detects faster-than-light motion in Galaxy M87". Baltimore, Maryland: Space Telescope Science Institute. http://www.stsci.edu/ftp/science/m87/press.txt. 
  50. ↑ Roy, Steve; Watzke, Megan (October 2006). "Chandra Reviews Black Hole Musical: Epic But Off-Key". Chandra. Harvard-Smithsonian Center for Astrophysics. http://chandra.harvard.edu/press/06_releases/press_100506.html. Retrieved 2010-04-25. 
  51. ↑ Cain, Fraser (October 27, 2006). "Gamma Rays Pour From the Edge of a Supermassive Black Hole". Universe Today. http://www.universetoday.com/2006/10/27/gamma-rays-pour-from-the-edge-of-a-supermassive-black-hole/. Retrieved 2010-04-25. 
  52. ↑ Harris, D. E.; Cheung, C. C.; Biretta, J. A.; Sparks, W. B.; Junor, W.; Perlman, E. S.; Wilson, A. S. (March 2006). "The Outburst of HST-1 in the M87 Jet". The Astrophysical Journal 640 (1): 211–218. doi:10.1086/500081. Bibcode: 2006ApJ...640..211H. 
  53. ↑ Harris, D. E.; Cheung, C. C.; Stawarz, L. (January 2009). "Variability Timescales in the M87 Jet: Signatures of E Squared Losses, Discovery of a Quasi-period in HST-1, and the Site of TeV Flaring". Bulletin of the American Astronomical Society 41: 393. Bibcode: 2009AAS...21333207H. http://arxiv.org/abs/0904.3925. Retrieved 2010-04-28. 

External links

Virgo constellation
Stars
Stars of Virgo
Bayer
α (Spica) • β (Zavijava) • γ (Porrima) • δ (Auva) • ε (Vindemiatrix) • ζ (Heze) • η (Zaniah) • θ • ι (Syrma) • κ • λ (Khambalia) • μ (Rijl al Awwa) • ν • ξ • ο • π • ρ • σ • τ • υ • φ • χ • ψ • ω • b • c • d¹ • d² • e • f • g • h • i • k • l • m • o • p • q • y • A¹ • A² • M
Flamsteed
1 (ω) • 2 (ξ) • 3 (ν) • 4 (A¹) • 5 (β, Zavijava) • 6 (A²) • 7 (b) • 8 (π) • 9 (ο) • 10 • 11 • 12 • 13 • 15 (η, Zaniah) • 16 (c) • 17 • 20 • 21 (q) • 25 (f) • 26 (χ) • 27 • 28 • 29 (γ, Porrima) • 30 (ρ) • 31 (d¹) • 32 (d²) • 33 • 34 • 35 • 37 • 38 • 40 (ψ) • 41 • 43 (δ, Auva) • 44 • 46 • 47 (ε, Vindemiatrix) • 48 • 49 • 50 • 51 (θ) • 53 • 54 • 55 • 56 • 57 • 59 (e) • 60 (σ) • 61 • 62 • 63 • 64 • 65 • 66 • 67 (α, Spica) • 68 (i) • 69 • 70 • 71 • 72 • 73 • 74 (l, "el") • 75 • 76 (h) • 77 • 78 (o, small Latin "o") • 79 (ζ, Heze) • 80 • 82 (m) • 83 • 84 • 85 • 86 • 87 • 89 • 90 (p) • 92 • 93 (τ) • 94 • 95 • 96 • 98 (κ) • 99 (ι, Syrma) • 100 (λ, Khambalia) • 102 (υ) • 104 • 105 (φ) • 106 • 107 (μ, Rijl al Awwa) • 108 • 109 • 110 • 1 Ser (M) • 2 Ser
Nearby
Ross 128 • Wolf 424 • FL (Wolf 424 B) • GL • Gliese 514 • Gliese 493.1 • Gliese 518 • Gliese 486 • GJ 1154 • 61 • GJ 3820
List
Galaxy cluster
Messier 49 · 58 · 59 · 60 · 61 · 84 · 86 · 87 · 89 · 90

Coordinates: Sky map 12h 30m 49.4s, +12° 23′ 28″

Messier objects
List
M1 · M2 · M3 · M4 · M5 · M6 · M7 · M8 · M9 · M10 · M11 · M12 · M13 · M14 · M15 · M16 · M17 · M18 · M19 · M20 · M21 · M22 · M23 · M24 · M25 · M26 · M27 · M28 · M29 · M30 · M31 · M32 · M33 · M34 · M35 · M36 · M37 · M38 · M39 · M40 · M41 · M42 · M43 · M44 · M45 · M46 · M47 · M48 · M49 · M50 · M51 · M52 · M53 · M54 · M55 · M56 · M57 · M58 · M59 · M60 · M61 · M62 · M63 · M64 · M65 · M66 · M67 · M68 · M69 · M70 · M71 · M72 · M73 · M74 · M75 · M76 · M77 · M78 · M79 · M80 · M81 · M82 · M83 · M84 · M85 · M86 · M87 · M88 · M89 · M90 · M91 · M92 · M93 · M94 · M95 · M96 · M97 · M98 · M99 · M100 · M101 · M102 · M103 · M104 · M105 · M106 · M107 · M108 · M109 · M110
See also
Catalogue of Nebulae · General Catalogue of Nebulae and Clusters · New General Catalogue · Index Catalogue · Revised New General Catalogue · Herschel 400 Catalogue · Caldwell catalogue
Wikipedia book Book:Messier objects · Category Category:Messier objects Portal Portal:Astronomy