Figure 10 gives a first estimation of the performance of the whole system (atmosphere + telescope + INTEGRAL + WYFFOS). This is based on data taken for the flux calibrator PG1708+602 (Massey et al., ApJ, 328, 315) under average observing conditions. These results were derived using the R1200B grating in 1.5 arcsec seeing. Repeated observations lead to a realistic uncertainty of about 0.5 mag. The background was removed by subtracting a sky exposure of equal observing time. No significant differences were found between the different bundles.
Figure: AB magnitude for obtaining 1 count/sec/Å, with INTEGRAL