"Onion-Galaxies" Thread

Let’s start a thread of galaxies that have many shells and layers. (As far as I know: “Interaction shells” I think they are called because they arise during gravitational interaction with other galaxies.)

I present two of my favorites to start out with:

https://www.legacysurvey.org//viewer/?ra=184.7138&dec=-6.7668&layer=ls-dr9&zoom=15

https://www.legacysurvey.org//viewer/?ra=46.6888&dec=-25.7151&layer=ls-dr10&zoom=15

I hope others have some more to add.

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https://www.legacysurvey.org//viewer/?ra=148.8925&dec=19.2970&layer=ls-dr9&zoom=14

Credit to William:

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PGC 409

https://www.legacysurvey.org//viewer/?ra=1.4360&dec=-39.7815&layer=ls-dr9&zoom=14

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NGC 474

https://www.legacysurvey.org//viewer/?ra=20.0274&dec=3.4156&layer=ls-dr9&zoom=13

Credit to William:

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there is another onion galaxy next to NGC 474

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Oh yes! Thank you. Sorry I didn’t see it myself.

https://www.legacysurvey.org//viewer/?ra=19.7934&dec=3.3016&layer=ls-dr9&zoom=13

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RA,Dec = 354.4113, 1.8198
Onion with a tail
(https://www.legacysurvey.org/viewer/cutout.jpg?ra=354.4072&dec=1.8191&layer=hsc-dr2&pixscale=0.50)

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this is probably one of the most studied I can find, not to the one like NGC 474.
NGC 3923

https://www.legacysurvey.org//viewer/?ra=177.7574&dec=-28.8050&layer=ls-dr10-grz&zoom


Link https://www.researchgate.net/figure/Fig-A11-Dust-in-the-central-parts-of-NGC-3923-MegaCam-image-Model-subtraction_fig7_277334178


Link shells-of-elliptical-galaxy-ngc-3923-in-hydra-c-rolf-wahl-olsen – Fubiz Media

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There is another galaxy that looks like the last one
AndyC’s galaxy
image
https://www.legacysurvey.org//viewer/?ra=354.4108&dec=1.8207&layer=hsc-dr3&zoom=14
IC 3091

https://www.legacysurvey.org//viewer/?ra=184.1219&dec=14.0134&layer=ls-dr9&zoom=12

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NGC 7736

https://www.legacysurvey.org//viewer-dev/?ra=355.6074&dec=-19.4517&layer=ls-dr10&zoom=13
g and i filters only

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Squashed onion and a dust-lane

https://www.legacysurvey.org//viewer/?ra=178.0525&dec=16.8524&layer=ls-dr9&zoom=13

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https://www.legacysurvey.org//viewer-dev/?ra=12.6353&dec=-8.6518&layer=ls-dr9&zoom=13

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Very nice thread. Astronomers usually call them “shell galaxies.” I could list like seven hundred of them :slight_smile:

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https://www.legacysurvey.org//viewer/?ra=338.0308&dec=-63.8596&layer=ls-dr9&zoom=13

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too pretty

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https://www.legacysurvey.org//viewer/?ra=29.1697&dec=33.0439&layer=ls-dr9&zoom=13

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https://www.legacysurvey.org//viewer/?ra=160.1182&dec=9.1845&layer=ls-dr9&zoom=12

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https://www.legacysurvey.org//viewer/?ra=145.9441&dec=11.4570&layer=ls-dr9&zoom=14

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