What's at the bottom of this pic a galaxy or her and why was it not part of the discovery process
Dam spell correct or a jet
I think the bright object at the bottom of the image is not part of the discovery process as there are no Radio Contours matching the Bright InfraRed.
You can use the slider below the image to look at either Radio or IR and you can also click on the survey names blow the image to see image from other surveys. The SDSS image doesn't show anything optical but If you click on WISE you can see a foreground Star in the same field of view.
I have to caveat my comment with I'm pretty new to this as well so I might be wrong.
It's a diffraction spike, or diffspike for short.
It's produced by light (IR in this case) from a very bright source (a star, most likely). The telescope has four 'vanes', which are mechanical supports for the secondary mirror; though they are about as thin as possible, they do distort the image somewhat, and produce four 'compass points' (among other, not-so-visible effects).
Here is the bright star that is likely creating the diffspike, as 'seen' by SDSS:
The orientation of the diffspikes depends on when the image was taken, and where, in the sky, the star was located (alt-azimuth for SDSS). The 'rainbow' change in colors, along each diffspike, is one of those not-so-visible effects.
why was it not part of the discovery process
Because it has nothing to do with radio sources, or their IR (or optical) counterparts. And they are well-known effects (if somewhat annoying).
Hope this helps, and happy hunting! 😃