of the AGB tip and age (as predicted from isochrones; Girardi et al. [@gir]), Sohn et al. ([@sohn]) find that most of the M-giants in formed between at $log(t_{yr})$ between $8.2-8.6$. In contrast, various authors found a significant amount of gas and dust in the centre of (Young & Lo [@yolo]; Lee et al. [@lee]; Martinez-Delgado & Aparicio [@MDA]; Martinez-Delgado et al. [@MDA2]). Butler & Martinez-Delgado ([@butler]) obtained an age of about $400$Myr for the youngest, centrally concentrated stars. Kang et al. ([@kang]) speculate that the M-giant population in contains stars with a wide range of ages, possibly representing two different epochs of star formation at $log(t_{yr})\approx 9.0-9.4$ and $7.8-8.5$dex. In the outer parts of stars with ages of at least $1$Gyr are found.

The red giant content of these galaxies was analysed by Nowotny et al. ([@wn], hereafter PaperI). The detected AGB stars were characterised according to the chemical properties of their atmospheres by applying an efficient method to single out stars, namely, the use of narrow-band wing-type filters that are centred around spectral molecular features of and (at $\lambda$$\approx$0.8$\mu$m). Within a field of view (FOV) of $6\farcm 5 \times 6\farcm 5$, the authors identified 154 stars in and 