This is a very fine picture of a fascinating galaxy.
I'd like to call attention to the large size of the disk. Note, too, that although the disk is slightly warped, the warp is not at all pronounced. For the most part, the disk looks "undisturbed".
Also note that although there are some bluish knots in the dust lane, indicative of young star clusters and recent star formation, these blue knots are neither bright nor numerous.
There are faint hints of pink in the dust lane, and there appears to be one definite emission nebula in the dust lane to the right of the bulge. But like the blue knots, the pink emission nebulae are faint and few.
There are signs of some activity in the dust lane. To the left of the bulge there are a pair of obvious "chimneys", where dust is blown up into the thick disk or possibly even into the halo of the galaxy by energetic processes in the dust lane. A likely cause would be past supernovae.
But again, the activity in the dust lane is not great. To me it seems that the activity in the dust lane of NGC 4565 is somewhat but not much greater than the activity in the dust lane of M104, seen here in a large Hubble picture
NGC 891. Photo: Jean-Charles Cuillandre
Compare the activity in the dust lane of NGC 4565 with the activity in the dust lane of similarly edge-on galaxy NGC 891. Clearly the activity in NGC 891 is much greater.
NGC 4565 is a considerably larger galaxy than NGC 891. It is a galaxy that must have seen huge amounts of star formation and also growth by cannibalization of smaller galaxies. More of the latter is to come, since there are still dwarf galaxies in the vicinity. But for now NGC 4565 is semi-retired, and it has "quieted down", settling itself on its throne like a fat old king.
Last edited by Ann on Thu Jul 05, 2012 1:43 pm, edited 1 time in total.