Messier 87
214077
224747401
2008-07-10T06:47:15Z
Sumanch
222446
{{Galaxybox begin
| name = [[Messier object|Messier]] 87<ref name="tonryetal2001">{{cite journal
| author=J. L. Tonry, A. Dressler, J. P. Blakeslee, E. A. Ajhar, A. B. Fletcher, G. A. Luppino, M. R. Metzger, C. B. Moore
| title=The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances
| journal=Astrophysical Journal
| year=2001
| volume=546
| issue=2
| pages=681-693
| url=http://adsabs.harvard.edu/abs/2001ApJ...546..681T
| doi=10.1086/318301
}}</ref>
}}
{{Galaxybox image
| image = [[Image:M87 jet.jpg|250px]]
| caption = A 5000 [[Light-year|ly]] jet produced by strong electromagnetic forces created by matter swirling toward the [[supermassive black hole]] in the center of the galaxy.
}}
{{Galaxybox observe
| epoch = [[J2000]]
| constell = [[Virgo (constellation)|Virgo]]
| ra = {{RA|12|30|49.4}}<ref name="ned">{{cite web
| title=NASA/IPAC Extragalactic Database
| work=Results for NGC 4486
| url=http://nedwww.ipac.caltech.edu/
| accessdate=2006-10-22}}</ref>
| dec = {{DEC|+12|23|28}}<ref name="ned" />
| appdim_v = 8.3 × 6.6 [[Minute of arc|moa]]<ref name="ned" />
| appmag_v = 9.59<ref name="ned" />
}}
{{Galaxybox character
| g_type = E+0-1 pec<ref name="ned" />, NLRG Sy<ref name="ned" />
}}
{{Galaxybox astrometry
| h_radial_v = 1307
| hrv_err = 7<ref name="ned" />
| z = 0.004360
| z_err = 0.000022<ref name="ned" />
| gal_v = 1254
| gv_err = 7<ref name="ned" />
| g_dist = 52
| dist_err = 4
}}
{{Galaxybox catalog
| names = Virgo A,<ref name="ned" /> [[New General Catalogue|NGC]] 4486,<ref name="ned" /> [[Uppsala General Catalogue|UGC]] 7654,<ref name="ned" /> [[Principal Galaxies Catalogue|PGC]] 41316,<ref name="ned" /> VCC 1316,<ref name="ned" /> [[Atlas of Peculiar Galaxies|Arp]] 152<ref name="ned" />
}}
{{Galaxybox reference
| Simbad = M87 Search M87
}}
{{Galaxybox end}}
'''Messier 87''' (also known as '''M87''', '''Virgo A''' or '''NGC 4486''') is a giant [[elliptical galaxy]]. The galaxy is the largest and brightest galaxy within the northern [[Virgo Cluster]], located about 60 million light years away.<ref>[http://adsabs.harvard.edu/cgi-bin/bib_query?1987AJ.....94..251B B. Binggeli, Bruno, G. A. Tammann, and A. Sandage, ''Astron. J.'' '''94''', 251 (1987).]</ref> The galaxy also contains a notable [[active galactic nucleus]] that is a strong source of multiwavelength radiation, particularly [[radio wave]]s.<ref name="baademinkowski1954">{{cite journal
| author=W. Baade, R. Minkowski
| title=On the Identification of Radio Sources
| journal=Astrophysical Journal
| year=1954
| volume=119
| pages=215-231
| url=http://adsabs.harvard.edu/abs/1954ApJ...119..215B}}</ref> Since this is the largest giant elliptical galaxy near Earth and since it is one of the brightest radio sources in the sky, it is a popular target for both [[amateur astronomy]] observations and professional astronomy study. M87 is estimated to have a mass, within 32 kpc of its center, of 2.4 ± 0.6 {{e|12}} [[solar mass|M<sub>☉</sub>]].<ref name="Wuetal2006">{{cite journal
| author=Wu, Xiaoan; Tremaine, Scott
| title=Deriving the Mass Distribution of M87 from Globular Clusters
| journal=The Astrophysical Journal
| year=2006
| volume=643
| issue=1
| pages=210-221
| url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006ApJ...643..210W
| doi=10.1086/501515
}}</ref>
== Globular clusters ==
M87 has an unusually huge population (perhaps the greatest known around any one galaxy) of [[globular cluster]]s as compared to the [[Milky Way]]'s 150-200. A [[2006]] survey out to 25′ of its core estimates that there are 12,000 ± 800 globulars around M87.<ref name="Tamuraetal2006">{{cite journal
| author=Tamura, Naoyuki; Sharples, Ray M.; Arimoto, Nobuo; Onodera, Masato; Ohta, Kouji; Yamada, Yoshihiko
| title=A Subaru/Suprime-Cam wide-field survey of globular cluster populations around M87 - I. Observation, data analysis and luminosity function
| journal=Monthly Notices of the Royal Astronomical Society
| volume=Online Early
| year=2006
| url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?doi=10.1111%2Fj.1365-2966.2006.11067.x }}</ref>
== Jet ==
In [[1918]], [[Lick Observatory]] astronomer [[Heber Curtis]] discovered a jet of matter coming from M87 which he described as "a curious straight ray". This jet extends at least 5000 light-years from the nucleus of M87 and is made up of matter ejected from the galaxy, most likely by a [[supermassive black hole]] (a fact made more likely by the discovery of a disk of rapidly rotating gas around the nucleus of M87). [[Astronomer]]s believe that the black hole in this galaxy has a mass of approximately 3 billion (3×10<sup>9</sup>) [[solar mass]]es. M87 has also been found to be a strong source of [[X-ray]]s. Its proximity means that it is one of the best studied [[radio galaxy|radio galaxies]].{{Fact|date=November 2007}}
===Superluminal motion===
In pictures taken by the [[Hubble Space Telescope]] in [[1999]], the motion of M87's jet was measured at four to six times the speed of light. This motion is believed 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 [[quasar]]s,
[[BL Lac object]]s and [[radio galaxies]] may all be the same phenomenon, known as [[active galactic nucleus|active galaxies]], viewed from different perspectives.<ref>[http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v520n2/39787/39787.html J. A. Biretta, W. B. Sparks, and F. Macchetto, ''Astrophys. J.'' '''520''', 621 (1999).;] {{cite web
| title=Hubble detects faster-than-light motion in Galaxy M87
| author=John Biretta
| publisher=Space Telecsope Science Institute
| location=[[Baltimore, Maryland]]
| url=http://www.stsci.edu/ftp/science/m87/press.txt
| date=1999-01-06}}</ref>
===X-ray emitting loops and rings===
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 M87. 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.<ref>[http://chandra.harvard.edu/press/06_releases/press_100506.html "Chandra Reviews Black Hole Musical: Epic But Off-Key"], [[October 2006]]</ref>
===Gamma ray emissions===
M87 is also a very good 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 M87 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 M87, and found that the flux changes over a matter of days.
It is generally accepted that the supermassive [[black hole]] located in the center of M87, holds a mass of several billion solar masses. However, the fact that the variations can change over several days makes the immediate vicinity of the supermassive black hole in M87 (about the size of our [[solar system]])<ref>[http://www.universetoday.com/2006/10/27/gamma-rays-pour-from-the-edge-of-a-supermassive-black-hole/ Universe Today, Gamma Rays Pour From the Edge of a Supermassive Black Hole], [[October 2006]]</ref> the most promising source of the gamma rays. In general, the smaller the diameter, the faster the variations, and vice versa.
== See also ==
* [[NGC 1316]]: a similar galaxy with a central supermassive black hole
* "[[New Earth]]": a 2006 episode of ''[[Doctor Who]]'' featuring a planet in M87. The planet was re-visited in the 2007 episode [[Gridlock (Doctor Who)|Gridlock]].
== External links ==
{{commons|Messier 87|Messier 87}}
*[http://www.seds.org/messier/m/m087.html Messier 87], SEDS Messier pages
*[http://simbad.u-strasbg.fr/sim-id.pl?Ident=M+87 Simbad data on M87]
*[http://www.spacetelescope.org/news/html/heic0204.html ESA/Hubble News Release]
*[http://www.spacetelescope.org/images/archive/freesearch/m87/viewall/1 ESA/Hubble images of M87]
*[http://astro.neutral.org/imagehtml/20060304_m87.html Amateur Images of M87 Jet]
*{{WikiSky}}
== References ==
{{reflist}}
{{Virgo}}
[[Category:Elliptical galaxies|Messier 087]]
[[Category:Peculiar galaxies|Messier 087]]
[[Category:Radio galaxies|Messier 087]]
[[Category:Virgo Cluster|Messier 087]]
[[Category:Virgo constellation|Messier 087]]
[[Category:Messier objects|087]]
[[Category:NGC objects|Messier 087]]
[[Category:UGC objects|07654]]
[[Category:PGC objects|41316]]
[[Category:Arp objects|152]]
[[Category:3C objects|274]]
[[bg:M87]]
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[[es:Galaxia elíptica M87]]
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[[it:Galassia Virgo A]]
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[[pl:Galaktyka Panna A]]
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[[ru:Эллиптическая галактика M87]]
[[sk:Virgo A]]
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[[uk:NGC 4486]]
[[zh:室女A星系]]