SMC Classification

[JaseD]

Hi,
I am curious as to why the Small Magellanic Cloud has numerous classifications. Yes, I understand that the early hubble scheme was inadequate and the people like de Vaucouleurs and Sandage revised it. However, the way Im reading is it should be under Hubble an Irr I. Now here is where it gets strange for my new to the system brain, all research points to it being under the dV&S system, an Im. yet when I use wiki, yeah I know credible source and the like :P but a few pages link from it; shows the SMC as an SB(s)m pec or peculiar barred spiral magellanic ...:shrug: I am hoping someone more learned than I can point me in the right direction.

Cheers
J.
:thanx:

[gary]

Hi Jase,

Indeed it is historical.

Early galaxy classification schemes go back as far as Wolf at Heidelberg in 1908.

Hubble classification is circa 1926.

de Vaucoulers circa 1956 and 1959.

Holmberg circa 1956.

Morgan circa 1959.

See https://ned.ipac.caltech.edu/level5/Sandage/paper.pdf

In some of these classification schemes, the SMC was regarded as the
prototype Type I irregular galaxy, hence the Im classification for
"Irregular Magellanic".

Tidal interactions between it and the Milky Way and between it and the LMC
(there is a bridge between the two referred to as "The Stream (http://hubblesite.org/news_release/news/2013-27/106-data)") have
distorted and obscured what structure it might have had in the distant
past or even possibly created new structure.

However, in more recent years, more detailed statistical analyses has been
performed on survey plates and using data collected from radiotelescopes.

Within the chaos of the SMC, there are possible hints of structure.

Maragoudaki et.al. reported in 2001 on the possibility that we may be
witnessing the formation of a bar structure within the SMC. But it
was uncertain at the time whether the observed isodensity is a "genuine
bar".
See https://www.aanda.org/articles/aa/pdf/2001/45/aah3136.pdf

Bastian et. al 2008 :-
https://arxiv.org/pdf/0809.1943.pdf


Subramanian et. al 2011 :-
https://arxiv.org/pdf/1109.3980.pdf

[JaseD]

Thanks Gary, sometimes asking is the hardest thing. I was struggling to understand but now, esp with the links has made galaxy classification much easier. :thanx:

[gary]

Thanks Jase,

You are most welcome.

In the domain of galaxy morphology, there are plenty of square pegs and
round holes, so it is not easy to classify them all.