The total observing time in the first 4 runs was ~77 hours. A total of
2029 frames (including 770 science frames and 583 calibration frames) were
collected. The raw data were stored on 10 high capacity DLTs (35Gb each)
totaling approximately 295 Gb. The following
table shows the number of frames for different type of data.
A determination of the photometric color term of the broadband filters of the WFI is presented. The data reduction was performed using Landolt (1992) calibration fields observed by the EIS team with the WFI.
The following figure shows the observed color terms of the B, V and I WFI filters. Only data for the WFI CCD#5 are plotted. In the left column the calibrations of B, V, R, and I filters (from top to bottom) against B-V are plotted; in the right column the calibrations are plotted against V-I. The B data are from stars in Selected Area 98, while for the V and I data are obtained from stars in the PG1323-086 field. In each panel the formal fit to the calibration data is also reported .
The color-terms obtained are confirmed by the computation of synthetic color terms. The following figure shows the color terms in the B, V, R, and I WFI filters (from top to bottom) simulated computing the expected magnitudes in each filter from the Pickles (1998) stellar spectral flux library. For the Johnson pass-bands, the transmission curves taken from the literature were applied. For the WFI we have used the filter transmission curves presented in the WFI La Silla filter page. Each filter has been convolved with the CCD response curve. In the left column the calibration against the B-V color in presented; on the right column the same calibration against the V-I color.
|Seeing map Patch C band B
||Photometric quality map Patch C band B
|Seeing map Patch D band B
||Photometric quality map Patch D band B
|Seeing map Patch D band V
||Photometric quality map Patch D band V
Some preliminary results are shown. An area of 1 sqdeg from the 3sqdeg in patch C in the coadded B-band image is selected. Relevant information can be found on the Pilot Survey image gallery page. The data has been analyzed using SExtractor.
|Comparison WFI vs EMMI|
The WFI is a highly efficient imaging device equipped with CCD detectors, which are very sensitive throughout the optical atmospheric window, from UV to near-IR. On this page the efficiency of the standard set of filters is compared to the past EIS filter set used at EMMI+NTT.
The total efficiency has been computed for each broadband filter presently available at the WFI (B, V, R and I). It includes the reflectivity of the mirrors (2 reflections), the absoptions of the optics of WFI, the CCD efficiency, and the transmission of each broadband filter. The result is shown in the following figure, where the green dashed lines are the transmission curves of the filters and the red continuous lines are the total efficiency of the filters (from left to right: B, V, R, I). Details on the filters can be found at the WFI filter page at La Silla.
The following figure shows the total efficency of the EIS filters (B, V and I) used by our team for the EIS-Wide Survey. Also in this case it includes the reflectivity of the mirrors (3 reflections), the absoptions of the optics of EMMI (Red arm), the CCD efficiency, and the transmission of each broadband filter. The green dashed lines are the transmission curves of the filters and the red continuous lines are the total efficiency for each filter (from left to right: B, V, I).
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Last update: Nov 16, 2000