Possible lens at high z-shift

https://www.legacysurvey.org//viewer/?ra=346.0515&dec=2.5049&layer=hsc-dr2&zoom=16

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" Possible lens at high z-shift"
What is the meaning of the above in simple words.
Really. I also invited ‘regular’ friends to come and explore the legacy-survey and to discover galaxies that no one spotted before them (us).
I want them (and me) to understand the discussions.

Ron

The further away a galaxy is, the more “stretched” the light reaching us from the galaxy becomes, owing to the expansion of the universe and the fact that more distant galaxies are moving away from us faster than ones close by. This is why the more distant galaxies in the images look red rather than the white or yellow colour of nearby galaxies. The amount by which the light spectrum is shifted towards the red end by this process is called the “red shift” or “z” and it is used as a measure of the galaxy’s distance. Wikipedia explains it in more detail. (I’m not an astronomer myself, so that is a very basic and possibly garbled explanation :upside_down_face:)

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