CFHT, Instruments, Spectroscopy, ESPaDOnS

ESPaDOnS: an Echelle SpectroPolarimetric Device
for the Observation of Stars at CFHT


In all observing modes, the following calibration frames are needed:

For the spectroscopic mode 'star only' and for the polarimetric mode, a Fabry-Perot exposure is also needed to better track the slit. Using a FP exposure for the 'star + sky' mode will not work.

The flat field exposures are used to find the orders, track them on the chip, fit their position, and produce a geometric calibration. The Thorium exposures are used for wavelength calibration (and to fit the shape and orientation of the slit in the 'star + sky' spectroscopic mode). The Fabry-Perot exposure is used to fit the shape and orientation of the slit.

All these calibrations can easily be taken through the GUI in Classical Observing, or are taken care of by the Service Observer in QSO mode.

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This CFHT Web page is maintained by Nadine Manset (manset -=AT=-