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3. V, I and Gunn z colour magnitude diagrams

V, I and Gunn z

We show in Fig. 2 (click here) a V vs (V-I) diagram for the whole frame; the V and I data are given in Table 2, available only in electronic form at the CDS-Strasbourg. Figure 2 (click here) shows a blue disk main sequence (MS), and a dispersed red giant branch (RGB) plus a Horizontal Branch (HB), in which the cluster and the bulge population are mixed.

In Fig. 3 (click here) is shown a V vs. (V-I) diagram for an extraction of radius r < 39'', where the cluster sequences are better defined than in Fig. 2 (click here). The center of the HB is located at tex2html_wrap_inline1187 and (V-I) tex2html_wrap_inline1191; the RGB is curved down indicating a high metallicity and reaching (V-I) tex2html_wrap_inline1195. The coolest RGB tip star is still present in a smaller extraction of radius r < 17''.

In Fig. 4 (click here) we plot I vs. (I-z), where the open circles correspond to stars inside a radius of r < 26'' (cluster) and crosses to stars of r > 39'' (mostly field), where the cluster sequences are more defined than for the field. The Subgiant Branch (SGB) is reached, the red HB is almost superimposed on the RGB, and the RGB is almost flat.

In Fig. 5 (click here) we show the Danish whole field. A strong differential reddening is present, indicated by the very elongated and tilted HB (tex2html_wrap_inline1207 mag.). The field RGB morphology suggests it to be somewhat more metal-rich than Ter 6 itself.

Copyright by the European Southern Observatory (ESO)