Quote:
.....Steven's UV-only image can potentially show us the location of these blue supergiant OB stars......
BUT
in long-wavelength UV images like Steven's, there is still substantial contamination of the image of NGC 5128 by light which comes from the old stellar population of this galaxy which we see as the spheroidal component of this galaxy......
Thus, in Steven's image, the light of the blue knots of young stars is somewhat confused with the light of the old stars in the spheroid of this galaxy......
|
From an imaging perspective this makes perfect sense as the original luminance image carries the RGB information from the visual image and is a "source" of the contamination.
With this in mind I have created a synthetic luminance image L=B+30*UV.
Here I have taken my existing B images and merged them with the 10 hr UV exposure where each pixel has been multiplied by 30.
The new luminance image is now in effect acting as a filter and is only allowing blue and UV light through and filtering out other wavelengths to a certain degree. The strongly red field stars are now largely muted and the outer envelope of Centaurus A is no longer visible.
The dust region is much more opaque looking.
The new image is found here.
http://members.iinet.net.au/~sjastro/CentUV_B.jpg
It's no longer a pretty picture but hopefully it might answer some questions.
Regards
Steven