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NGC 5128 | by Dave & telescope
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NGC 5128

NGC 5128 in the constellation of Centaurus is the closest known “radio” galaxy at a distance of about 12 million light years. The result of a merger between an elliptical galaxy and a spiral galaxy, it displays a wide variety of kinematic features.

The remnant of the original spiral galaxy is represented by its central dust lane.

Cosmic collisions between galaxies trigger a massive outburst of starforming activity as the neutral gas reservoir is increased and pressure and gravity compress gas clouds into active sites of starbirth. The original collision has also strewn small dust globules which can be seen across the disk of the galaxy.

This intergalactic encounter between two galaxies has also deformed the structure of the original elliptical galaxy and faint tidal shells envelop the galaxy. The edges of one or 2 of these can be faintly seen within the giant gas cloud. They were originally discovered by the astronomers David Malin and David Carter in the 1970's through special photographic amplification techniques. Their discovery prompted the publication of a catalogue of shell elliptical galaxies in 1983 and there are a few hundred known to belong to this category.

NGC 5128 is also known as Centaurus A and this particular naming scheme denotes the first radio source to be discovered in a particular constellation. As it has been detected by astronomers in observations made with radio telescopes, it belongs to another category of radio galaxies. Radio galaxies are so-called as they radiate more emission in radio than in optical. They are a type of active galactic nucleus (usually abbreviated to AGN). As the name suggests, galaxies that feature an AGN have an energetic nuclear region centered around a supermassive black hole.

Although not immediately apparent, the AGN activity in Centaurus A is represented optically by a long filamentary jet, a portion of which can be seen here pointing toward the lower left corner of the image. The jet arises from an outflow of gas that has built up in the accretion disk surrounding the supermassive black hole and its narrow appearance is the product of interacting magnetic fields associated with the black hole. This jet appears as an impressive bipolar outflow in x-ray and radio images.


Capture info:

Telescope- 500mm f/3.6 ASA newtonian

Camera- FLI 16803

Duration- about 35 hrs total LRGB


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Uploaded on February 7, 2020