Really terrific image.
I did a general inspection of this and Megastar 5.0 on my MAC, and found some interesting comparisons. It is good to identify some of the fainter stuff in this image. Interestingly is the bottom the little spiral arm in the image has two little condensations instead of one.
It is also interesting to read about this system in the NASA/IPAC Extragalactic Database,
http://nedwww.ipac.caltech.edu/forms/byname.html especially what is written in the Notes section , which appears also in the Alan Sandage and John Bedke's "The Carnegie Atlas of Galaxies. Vol 1.
"The unusual plumes in NGC 1532 suggest a tidal distortion due to an encounter. The evident candidate responsible for the perturbation is the amorphous companion NGC 1531, whose morphology is of the same class as M82. The two galaxies form a physical pair; the redshifts are v_o(1531) = 1053 km/s and v_o(1532) = 1105 km/s.
Three dwarf candidate companions form a wider physical group centered on the bright pair. The most interesting of the companions is at RA (1950) 4h 10m 56s, Dec (1950) = -33 deg 07' 36". It appears as a dwarf S0(8),N on a yellow plate but as an Im with condensations on a blue plate, similar to the transitional (Im-dE,N) case of NGC 4286 (panel 20) (Sandage and Hoffman 1991). The low ratio of the hydrogen mass to total mass also suggests that the dwarf is in transition between Im and dE,N dwarf types (Sandage and Fomalont 1993).
The other two dwarf candidate companions are a high-surface-brightness SB0 (M = -19) at RA (1950) 4h 10m 39s, Dec (1950) = -32 deg 56' 33", and a prototype faint dE0,N nucleated dwarf elliptical at RA (1950) = 4h 09m^ 32s, Dec (1950) = -32 deg 59' 09"."
They say of the bright companion;
"NGC 1531, here, is a close companion of NGC 1532 (Sbc; panel 197); the pair is presently in a close encounter. The enlargement of this print is great enough to exclude any part of NGC 1532 (panel 197) which is at an angular separation greater than 1.8'. A description of the pair and the
peculiar morphology of NGC 1532 is on panel 197.
NGC 1531 has an amorphous texture to its luminosity distribution; there is evidence of dust in the image."
Much of what you have captured here appears in these descriptions.
I was also wondering if you have cropped this image in any way, as there are galaxies to the eat - especially the other companion IC 2041, which is just above the top portion of the image.
Thank you for sharing this image with us.
Note: I've attached the 32 arcmin field from Megastar 5.0.
