2. OBSERVATIONS AND DATA REDUCTION

2.1. Observations

The observations were carried out on September 7 and 8, 2002, with the imager/spectrograph DoLoRes at the 3.52m Italian telescope Telescopio Nazionale Galileo (TNG) in La Palma (Canary Island, Spain). DoLoRes is equipped with a 2048 × 2048 pixel thinned and back-illuminated Loral CCD array with a total field of view of 9'.4 × 9'.4, and a scale of 0.275 "/px. The seeing was remarkably good and stable, ranging between 0.8" and 1.1" FWHM for all the scientific images.

Two fields were imaged along the minor axes in V and I filters. The locations of the fields are shown in Figure 1 and listed in Table 1 along with the date, the filter and the exposure time of all the scientific exposures. A total of 7 V and 6 I 600 s exposures have been acquired for the inner field (Field 1, hereafter F1) and 8 V and 6 I 600 s for the outer field (Field 2, hereafter F2). The distance of the field center from the center of the galaxy is 15' for F1 and 28' for F2.