Hi Ivan & All,
Yes, as Ivan has noted ESO 270-17 is a possible/probable merger remnant/shred remaining from the merger event that gave Centaurus A* its current appearance. NGC 5237 is the possible merger remnant core. At first glance, ESO 270-17 looks like an edge-on spiral but it is definitely not rotating, has no core and is slowly stretching along its major axis.
This is the 1992 paper that results from supercomputer simulations that demonstrates in principle, that a prograde merger between a massive lenticular galaxy like NGC 5128 and a dust-rich spiral can produce a result not unlike what we see with these three objects (currently).
https://academic.oup.com/mnras/artic.../4/689/1092606
Observing notes from 1999 under a Bortle 2 sky (Mudgee Star Party):
PGC 47847 (ESO 270-17) Gx Centaurus
31cm x186: An extremely faint galaxy of very, very LSB but large. In a pretty starry field as an ill-defined streak, almost non-existent patch of weakest gossamer 6' x 1' in PA 110 with a line of stars not superimposed but running beside it magnitudes 10-11. Does not grow to the axis or the core. Very, very difficult object at threshold.
I don't have a note using 46cm, but I do recall re-observing it a few times about 10 years ago at x185. It was still a very difficult object of exceedingly LSB but a bit easier to see than with 31cm. I have looked at it once with 63.5cm at x156 and it is much more definite, still very LSB, maybe 8' long with a slightly brighter centre.
Best,
L.
P.S ESO 274-1, an edge-on spiral in Lupus is also a probable member of the M83/Centaurus A* group. A little easier to see than ESO 270-17 but in a field with a veritable blizzard of stars.
PGC 54392 (ESO 274-1) Gx Lupus (1999)
31cm x186: A quite difficult object of extremely LSB. Visible N of a magnitude 8 star by 14'. In a field with a gazillion other faint stars. In PA 45 as a very long diaphanous streak of gossamer 7-8' x 1' in PA 45. Small slightly brighter portion near the centre, otherwise of consistent LSB except that the tips are even fainter than most of the halo. Quite a number of faint stars and threshold stars are superimposed. Very, very lovely!