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The '''Black Eye Galaxy''' (also called '''Sleeping Beauty Galaxy'''; designated '''Messier 64''', '''M64''', or '''NGC 4826''') was discovered by [[Edward Pigott]] in March 1779, and independently by [[Johann Elert Bode]] in April of the same year, as well as by [[Charles Messier]] in 1780. It has a spectacular dark band of absorbing dust in front of the galaxy's bright nucleus, giving rise to its nicknames of the "Black Eye" or "Evil Eye" galaxy. M64 is well known among [[amateur astronomy|amateur astronomer]]s because of its appearance in small [[telescope]]s. It is a [[spiral galaxy]] in the [[Coma Berenices|Coma Berenices constellation]]. |
The '''Black Eye Galaxy''' (also called '''Sleeping Beauty Galaxy'''; designated '''Messier 64''', '''M64''', or '''NGC 4826''') was discovered by [[Edward Pigott]] in March 1779, and independently by [[Johann Elert Bode]] in April of the same year, as well as by [[Charles Messier]] in 1780. It has a spectacular dark band of absorbing dust in front of the galaxy's bright nucleus, giving rise to its nicknames of the "Black Eye" or "Evil Eye" galaxy. M64 is well known among [[amateur astronomy|amateur astronomer]]s because of its appearance in small [[telescope]]s. It is a [[spiral galaxy]] in the [[Coma Berenices|Coma Berenices constellation]]. |
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==Properties== |
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The [[interstellar medium]] of Messier 87 comprises of two [[Retrograde and prograde motion|counter-rotating disks]] which are approximately equal in mass<ref name="1992Nature360,442">{{cite journal|author=R. Brawn, R. A. M. Walterbos & Kennicutt R. C.|year=1992|title=Counter-rotating gaseous disks in the "Evil Eye" galaxy NGC4826|journal=[[Nature (journal)|Nature]]|volume=360|page=442|bibcode=1992Natur.360..442B}}</ref>. The inner disk contains the prominent [[cosmic dust|dust lanes]] of the galaxy. The stellar population of the galaxy exhibits no measurable counterrotation<ref name="1995ApJ438,155">{{cite journal|author=H.-W. R. Rix, R. C. Kennicutt & R. A. M. Walterbos|year=1995|title=Placid stars and excited gas in NGC 4826|journal=[[Astrophysical Journal]]|volume=438|page=155|bibcode=1995ApJ...438..155R|doi=10.1086/175061}}</ref>. Possible formation scenarios include a merger with a gas-rich satellite galaxy in a retrograde orbit or the continued accretion of gas clouds from the [[intergalactic medium]]<ref name="1992Nature360,442" /><ref name="1995ApJ438,155" />. |
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At first glance, M64 seems to be a fairly normal spiral galaxy. As in the majority of galaxies, all of the stars in M64 are orbiting in the same direction, clockwise as seen in the Hubble image. |
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However, recent detailed studies have led to the remarkable discovery that the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the inner regions. The inner region has a radius of only approximately 3,000 light-years, while the outer section extends another 40,000 light-years. This pattern is believed to trigger the creation of many new stars around the boundary separating the two regions. |
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==Collision with neighbor galaxy== |
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A collision of two galaxies has left a merged star system with an unusual appearance as well as bizarre internal motions. Astronomers believe that the oppositely rotating gas arose when M64 absorbed a satellite galaxy that collided with it, perhaps more than one billion years ago. Active formation of new stars is occurring in the shear region where the oppositely rotating gases collide, are compressed, and contract. |
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Particularly noticeable in the image are hot, blue young stars that have just formed, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to [[ultraviolet]] light from newly formed stars. It is approximately 17 million light years from Earth. The small galaxy that impinged on its neighbour has now been almost completely destroyed, while its stars have either entered the main galaxy or scattered into intergalactic space, but signs of the collision persist in the backward motion of gas at the outer edge of M64. |
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==References== |
==References== |
Revision as of 09:06, 30 December 2013
Template:Galaxybox begin Template:Galaxybox image Template:Galaxybox observe Template:Galaxybox character Template:Galaxybox astrometry Template:Galaxybox catalog Template:Galaxybox reference Template:Galaxybox end The Black Eye Galaxy (also called Sleeping Beauty Galaxy; designated Messier 64, M64, or NGC 4826) was discovered by Edward Pigott in March 1779, and independently by Johann Elert Bode in April of the same year, as well as by Charles Messier in 1780. It has a spectacular dark band of absorbing dust in front of the galaxy's bright nucleus, giving rise to its nicknames of the "Black Eye" or "Evil Eye" galaxy. M64 is well known among amateur astronomers because of its appearance in small telescopes. It is a spiral galaxy in the Coma Berenices constellation.
Properties
The interstellar medium of Messier 87 comprises of two counter-rotating disks which are approximately equal in mass[1]. The inner disk contains the prominent dust lanes of the galaxy. The stellar population of the galaxy exhibits no measurable counterrotation[2]. Possible formation scenarios include a merger with a gas-rich satellite galaxy in a retrograde orbit or the continued accretion of gas clouds from the intergalactic medium[1][2].
References
- ^ a b R. Brawn, R. A. M. Walterbos & Kennicutt R. C. (1992). "Counter-rotating gaseous disks in the "Evil Eye" galaxy NGC4826". Nature. 360: 442. Bibcode:1992Natur.360..442B.
- ^ a b H.-W. R. Rix, R. C. Kennicutt & R. A. M. Walterbos (1995). "Placid stars and excited gas in NGC 4826". Astrophysical Journal. 438: 155. Bibcode:1995ApJ...438..155R. doi:10.1086/175061.