The SP has six focal stations for science bundles (see Figure 4). However, only three bundles are mounted in the standard configuration. The different SP positions are described in Table 1.
These bundles were manufactured by the IAC, using Ceramoptec fibres. The bundles sb1 and sb2 use `ultradry special' hydrogen treated fibres. Bundle sb3 uses Optram `UV' fibres. Each is 5.5m long. Their spectral response can be found in figures 7 and 8.
Figure 7: Transmission of the fibers (5.5m) used for sb1 and sb2, according to the fiber manufacturer
Figure 8: Transmission of the fibers (5.5m) used for sb3, according to the fiber manufacturer
At the focal plane the fibres are arranged in two groups, one forming a rectangle, and the other a ring which is intended for collecting background light (for small-sized objects). Table 2 and Figure 9 show the main characteristics of each bundle.
|1 - fibre core diameter (arcsec)|
|2 - fibre image size on the detector (to be convolved with a 1.4-2.6 pixel PSF)|
|3 - total number of fibres (rectangle + ring)|
|4 - spatial coverage of the central rectangle (arcsec arcsec)|
|5 - distance between adjacent fibre/spectra at the CCD (in pixels)|
|6 - diameter of the outer ring (arcsec)|
For each bundle the fibre correspondence between the focal plane and slit position is given in Appendix 1.
Figure 9: Configuration of the fibres of the standard bundles, at the focal plane end.