Differentiating the choices
-
by beng5113
How can I differentiate a smooth+cigar shaped from disk+edge on+no bulge?
Posted
-
by JeanTate in response to beng5113's comment.
Welcome to Galaxy Zoo, beng5113!
In a word, with great difficulty! ๐ฎ
A rule-of-thumb I use for 'edge-on' is 'does it have pointy ends?' (if so, it's an edge-on). If the galaxy is big enough - takes up enough pixels - you can sometimes distinguish 'smooth+cigar shaped' from 'disk+edge on+no bulge' by how sharp the nucleus appears ... 'smooth+cigar shaped' will have a smooth gradient with no sharp breaks, but 'disk+edge on+no bulge' will have just such a break. Also, highly inclined disks - not quite edge-on, so they look cigar shaped - may have structure, a hint of an arm or a bar perhaps, or a ring or lens. None of this helps much if the galaxy is small, of course. ๐ฆ
Ultimately, however, it's your choice, call it as you see it (there is no "right" answer).
Happy hunting! ๐
Posted