red arc or overlap?
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lodilady
6 o'clock red arc by large ?merging galaxies. Or is everything an overlap?
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JasonJason
That also looks like there is an arc on the left also I would have marked that one too.
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Budgieye
moderator
That is an interesting one! Can arcs be orange? Quasars can be orange, and can be lensed, but I don't think they can be lensed into arcs, just the double and quad patterns.
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anupreeta
scientist, admin
Lensed galaxies or quasars can have reddish / yellowish colors but are not as abundant as bluish galaxies and quasars.
Budgieye - you are right - quasars can't be lensed into an arc, they are point-like. But quasars are located inside galaxies and due to high magnification / distortion, sometimes you can find arc-like light underneath a lensed quasar which is the lensed emission of the "host" galaxy.
e.g. reddish arcs underneath the bright quasars -- http://imgsrc.hubblesite.org/hu/db/images/hs-2006-23-a-wallpaper_preview.jpgBtw, the 6'o clock arc is too straight given its proximity to the two galaxies. Just imagine extending the arc to form a circle -- very roughly, the center of the circle is where you'd expect the lensing galaxy/galaxies to be. Both the arcs on the left and right sides, don't have the right curvature to be lensed by the pair of galaxies.
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