FORS1 & FORS2, the UV-visual Focal Reducing / Low Resolution Spectrographs of the ESO/VLT (FORS1 decommissioned, FORS2 workhorse[1] of the VLT)


Fig.1: The opto-mechanical flexure compensation developed through the Astrophysical Institute at Göttingen ensures a specificaly sharp and stable imaging e.g. for weak-lensing and cosmic-shear detection of the twin instruments, the FOcal Reducing and low resolution Spectrographs FORS1 (here in background at Unit Telescope UT1) and FORS (in the foreground attached to the Unit Telescope UT2).

Project description: in preparation

[1] Rupprecht, G., Böhnhardt, H., Möhler, S., Möller, P., Saviane, I., Ziegler, B., 2010: Twenty Years of FORS Science Operations on the VLT, ESO, The Messenger 140, 2
[2] Seifert, W., Mitsch, W., Nicklas, H., Rupprecht, G., 1994 : FORS: a workhorse instrument for the ESO VLT, SPIE 2198, 213
[3] Nicklas, H. et al., 1997: Construction of the FORS Focal Reducer/Spectrographs: status report and first test results, SPIE 2871, 1222
[4] Böhnhardt, H., Möhler, S., Hess, H.J., Kiesewetter, S., Nicklas, H.,1995: Design benchmarks of the FORS instrument for the ESO VLT, Internat. Symp. on the Scientific and Engineering Frontiers for 8-10m Telescopes, p. 199
[5] Appenzeller, I. et al., 2000, Science with FORS, Springer, ISBN: 3-540-67163-3
[6] Heidt, J. et al., 2001: The FORS Deep Field, Reviews in Modern Astronomy 14, 209
[7] Heidt, J. et al., 2003: The FORS Deep Field: Field selection, photometric observations and photometric catalog, Astron. & Astrophys. 398, 49
[8] Heidt, J. et al., 2003: The QSO Q0103-260 (z=3.36) in the FORS Deep Field, Carnegie Obs. Astrophys. Ser. 1