Quote:
Originally Posted by jase
Thanks Robert. I'd be interested to know the final classification given the galaxy's complex nature once more information comes to hand.
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I would like to send a link to your I5332 image, to Professor Ron Buta (Univ. of Alabama), who is a leading authority on galaxy classification.
(the Science Forum contains a link to his recent comprehensive review of galaxy morphology)
But it is hard to know if there would be enough interest among the "pros" to make a serious study of this galaxy. Its morphology is distinctive, but not absolutely unique.
One probably shouldn't get too obsessed with assigning a single Hubble class/type to each galaxy, as so many specific galaxies do not exactly correspond to a specific Hubble type.(for instance, there exist
smooth-armed spiral galaxies that have a
small bulge)
Hubble classes are essentially a
convenient shorthand for describing, in a rough and ready way, what sort of galaxy we are talking about. However, within each Hubble type, there is a very large range of galaxy morphologies.
IC 5332 is in fact a good example of a galaxy that
cannot readily be assigned a single unique type within the orthodox Hubble Sequence
(E - S0 - S0/a - Sa - Sb - Sc - Scd - Sd - Sm - Irr)
The inner spiral structure (quiescent ; yellow ; smooth ; two-armed) would in fact be more typical of an
Sa galaxy.
In contrast, the more outer spiral structure (strongly star-forming ; blue ; entropic ; multiple-armed) corresponds much more to that which you would find in a galaxy that is later in the Hubble Sequence, perhaps a galaxy of
type Sd.
So the template of a single Hubble class (type) is not very useful in the case of this galaxy;
it is a case of "either this type, or that type, or, more properly,
both types".
Strange, but true!
As Obi Wan Kenobi said "these are the truths that we must cling to, Luke".
cheers, Mad Galaxy Man