M giant populations and galactic structure

JHKL photometry is given for 63 local M giants, for 195 M-giants outside the galactic plane and for 34 M-giants which are known semi-regular variables. Using the (J-H)0-(H-K)0 diagram a comparison is made with recently published models and with the M-giant population in the NGC 6522 Baade window of the Galactic Bulge. Our results show that there are M giants in the extended solar neighbourhood at distances of about 500 pc or more from the galactic plane which lie in the same region of the (J-H)0-(H-K)0 diagram as the M giants in the NGC 6522 field. The present work gives reasons for supposing the progenitors of Mira variables in the Galactic Bulge and in the extended solar neighbourhood are similar. (author)