Centaurus A

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Centaurus A (NGC 5128)
Firestorm of starbirth in galaxy Centaurus A

Centaurus A or NGC 5128 is a prominent galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop at his home in New South Wales, Australia.

NGC 5128 is either a Hubble type lenticular galaxy or a elliptical galaxy. It is 10–16 million light-years away.[1][2][3]

NGC 5128 is one of the closest radio galaxies to Earth. Its active center has been well studied.[4] The galaxy is the fifth brightest in the sky,[4] and is an ideal amateur astronomy target.[5] The galaxy is only visible from low northern latitudes and the southern hemisphere.

The center of the galaxy has a supermassive black hole. Its mass is about 55 million solar masses.[6] This ejects a relativistic jet with emissions in the X-ray and radio wavelengths. Astronomers have taken radio observations of the jet ten years apart. They found that the inner parts of the jet are moving at about half the speed of light. X-rays are produced further out as the jet collides with surrounding gas. This produces highly energetic particles. The radio jets of Centaurus A are over a million light years long.[7]

Like other starburst galaxies, a collision produced the intense burst of star formation. Spitzer Space Telescope studies have confirmed that Centaurus A is colliding with, and devouring, a smaller spiral galaxy.

References[change | edit source]

  1. Harris, Gretchen L.H. et al 2010. The distance to NGC 5128 (Centaurus A). Publications of the Astronomical Society of Australia 27 (4): 457–462. [1]
  2. Harris, Gretchen L.H. 2010. NGC 5128: The giant beneath. Publications of the Astronomical Society of Australia 27 (4): 475. [2]
  3. Tonry J.L. et al 2001. The SBF survey of galaxy distances. IV. SBF magnitudes, colors, and distances. Astrophysical Journal 546 (2): 681–693. [3]
  4. 4.0 4.1 F. P. Israel (1998). "Centaurus A - NGC 5128". Astronomy and Astrophysics Review 8 (4): 237–278. doi:10.1007/s001590050011.
  5. Eicher D.J. (1988). The Universe from your backyard. Cambridge: Cambridge University Press. ISBN 0-521-36299-7.
  6. "Radio telescopes capture best-ever snapshot of black hole jets". NASA. http://www.nasa.gov/topics/universe/features/radio-particle-jets.html. Retrieved 2012-10-02.
  7. "Astronomy Picture of the Day - Centaurus radio jets rising". NASA. 2011-04-13. http://apod.nasa.gov/apod/ap110413.html. Retrieved 2011-04-16.