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Reprocessed GALEX image of Centaurus A
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Reprocessed GALEX image of Centaurus A

April 18, 2005
This is the peculiar galaxy Centaurus A, which is 30 Million light years from Earth. This picture is a combination of the GALEX Far UV image (colored blue) the GALEX Near UV image (colored green and an image taken by NASA's great observatory Chandra (colored red) that measures the X-ray emission from around this galaxy.

There are some detector artifacts in this early processing of the GALEX data. The small darker areas in the image are the result of removal of detector blemishes (called "hotspots") from the image. The faint oval of UV light on the left side of the image is a result of multiple reflections of the UV light from the bright star in the center left of the image.

This bight star is also the cause of the small faint circle of UV light just to the left of Centaurus A. This circle is formed from a reflection in the dichroic crystal used to split the UV light into the NUV and FUV bands.

Centaurus A has a prominent dust lane that absorbs the ultraviolet light from the stars in the galaxy. This galaxy has a super massive black hole at its center that emits jets of high energy particles, traced by the X-ray emission observed by Chandra. At the intersection of the jets and clouds of Hydrogen gas approximately 50,000 light years away from the galaxy, several regions of Ultraviolet (UV) emission can be seen in the North-East (upper left) just beyond the X-ray emission. This UV light may be from young stars formed in a burst of recent star formation triggered by the compression of the gas clouds by the X-ray jet.

The updated processing of the GALEX data, shown here, has removed the detector blemishes by correctly accounting for the true exposure time at each point in the image.


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