This poster is a collection of superthin galaxies that I have imaged. I rank ordered them by their length-to-width axis ratio. Initially, for the ordering, I relied upon their published ratio. But I found the published ratios to be wildly inconsistent, so I calculated my own ratios for this poster. They range from 10 to 18. Determining the ratio is subjective since there is no real hard “edge” to any galaxy. I estimated where the star density dropped off to near the background sky level. Also, the width varies along the length, so I took an average value in the middle section.
The structure of superthin galaxies seems a bit unreal to me. It is hard to imagine that a galaxies could be this thin. Few of these galaxies have a central bulge.
The formation mechanism for superthin galaxies is not well understood. It is interesting that there are not many of them out there. Perhaps their formation requires an absence of disturbance, a minimal central bulge, and the presence (or absence?) of a dark matter halo.
Here is a list of the galaxies on the poster:
- UGC 9242 14h25m21s +39.53872 Boo
- UGC 711 01h08m37s +01.64053 Cet
- IC 2233 08h13m59s +45.74239 Lyn
- UGC 3697 07h11m22s +71.83611 Cam
- NGC 5529 14h16m19s +36.21389 Boo
- NGC 100 00h24m03s +16.48597 Psc
- NGC 4244 12h17m30s +37.80758 CVn
- NGC 4762 12h52m56s +11.23033 Vir
- NGC 5907 15h15m54s +56.32903 Dra
- NGC 891 02h22m33s +42.3483 And
- NGC 2357 07h17m41s +23.35581 Gem
- NGC 4302 12h21m42s +14.59858 Com
It is odd that none of them are in the southern hemisphere. I live at about +30, but plenty of the objects I image are in the southern hemisphere.
Below are the galaxies which just missed the cut, all at a length-to-width ratio of slightly less than 10:
- NGC 4565
- NGC 973
- NGC 2820
- NGC 5965
- UGC 10043
- UGC 10273
- UGC 10641
- NGC 4222
- LEDA 17217
- NGC 4111
If you would like to read more about any of these objects, each of the objects in the poster has previously been uploaded and described individually on Astrobin. They all reside in my
Astrobin Superthin Galaxies Collection.
If you would like to access all my DSO compilation posters, please click
here.
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