1. Optical Spectro-Imagers
IOT Overview Talk
The 2007 ESO Instrument Calibration Workshop Garching, January 23-26, 2007
Nando Patat
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

2. ESO’s spectro-imagers long tradition
April 1985: ESO 3.6
After that, many followed…
(EFOSC2, DFOSC  ALFOSC, n x _FOSC)
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

3. EFOSC2
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

4. FORS1
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

5. VIMOS
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

6. Multi-Mode Instruments
EF2
EMMI F1 F2
VIMOS
IMG x
IMG/OCC
LSS
MOS
LPOL
CPOL *
Calibration Plan is quite busy!
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

7. An example: FORS CalPlan
What is supported:
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

8. An example: FORS CalPlan
And what is not supported…
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

9. QC0 & Daily Health Checks
M1 Aluminization
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

10. 0.13 mag yr-1 M1 Efficiency Losses
A: Cond.; B: M1 re-aluminisation; C: UT1>>UT3
0.13 mag yr-1
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

11. Quality Control
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

12. The long standing issue of photometric calibration…
Landolt’s stars are too bright for 8m-class telescopes…
IOT is investigating alternative possibilities (WG chaired by P.Møller)
We still lack an absolute extinction monitor
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

13. 21:35
F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

14. Sky transparency variations are monitored by the LOSSAM
Line of Sight Sky Absorption Monitor
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

15. Multiplexing adds complexity…
See poster by S. Mieske et al. R
Overall efficiency per quadrant
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

16. Talking about photometric accuracy…
The CP insures a 5% accuracy
Can we do better?
(see W. Freundling’s talk)
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

17. Flat fielding focal-reducers IS an issue…
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

18. 1
The FORS1’s Big One
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

19. And what about fringing?
Solutions do exist, even though here one is confronted with something we cannot control (yet), i.e. the night sky.
(see also poster by Kuntschner et al.)
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

20. Indeed, with modern instruments
(at least those discussed here) it seems like we have reached a level where calibrating the instrument is the easiest part and what really dominates the whole process is calibrating the atmosphere…
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

21. A FORS1 IOT Media Production The Dancing Night Sky
A movie by
FORS1
A FORS1
IOT
Media Production
The Dancing Night Sky
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

22. Six years of FORS1 night sky monitoring
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

23. 21:35
F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

24. 21:35
F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

25. And what about the twilight sky?
Twilight skyflats
Phot. standards
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

26. Second order contamination (F1/2)
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

27. Second order contamination (F1/2)
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

28. Ongoing and Planned Activities
Derive flexure models for both FORSes
Derive offsets of the various filters
VPH Grisms off-axys response
HIT mode CalPlan (currently none)
Accurate definition of FORS photometric system
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

29. Are we sure we are doing it right?
This is why
we are here…
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop

30. FORS1 Blue CCD Upgrade IOT: People on the Move
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F. Patat – Optical Spectro/Imagers -The 2007 ESO Instrument Calibration Workshop