1. GSC2 @ ESO: Applications to the ESO Imaging Survey and to the VLT
R.Mignani (ESO)
7th GSC2 Meeting
2001

2. ESO Imaging Survey (www.eso.org/eis)
The ESO Imaging Survey (EIS) is a pilot project in preparation for VST (2003) and VISTA (2004)

3. ESO Imaging Survey
EIS carried on with (34x33 arcmin 8 chips mosaic CCD)
GSC2 is now used in the EIS pipeline for astrometric calibration of the survey fields
The Deep Public Survey (DPS) (started fall ‘99) covers 3 (0.5x2 deg) patches in UBVRI + JKs, including Chandra Deep Field South
EIS CDFS observations relased early this year (Vandame et al A&A- accepted; Arnouts et al A&A in press)- test release of GSC2.1 used (<0.1” rms)- data will be rereleased asap with GSC2.2 astrometry
The Pre-FLAMES Survey (PFS) covers 160
(0.5x0.5 deg) fields in BVI - GCs, OCs, LMC, SMC,
GB ... targets for the SV of
The GOODS/ESO observations of the CDFS tbd
with

4. GOODS/ESO coverage

5. EIS coverage

6. NGC1904

7. FLAMES@KUEYEN FLAMES is a Fiber system feeding GIRAFFE and UVES
MOS (Commissioning end of 2001)
GIRAFFE in MEDUSA mode is
fed by 130 fibers (1.2” diam)
Automatic ACQ
Very stringent requirements on
the astrometry (< 0.2”)
Challenge for the GSC2
First data released so far:
4 OCs: Berkeley 20, NGC 2477,
NGC2506, M67
2 SMC Fields: NGC330,NGC346
Momany et al 2001 A&A-in press

8. USNOA2.0 vs GSC2.2 Test computed wrt the M67 field

9. RA,DEC residuals vs RA,DEC

10. RA,DEC residuals vs mag

11. USNOA2.0&GSC2.2 vs Ref Astrometry compared vs Reference astrometry of M67 field (Girard et al AJ 98, 227)

12. Landolt vs GSC2
Visual inspections on the DSS have shown that Landolt stars are off from the nominal positions (Landolt 1992 AJ 104,340)
In some cases, differences up to few arcmin have been found
Unknown PMs (to be measured)
Errors in the original Astrometry
Pbs for automatic recognition of
standards and photom pipelines
Reassessment of Landolt coo
in the GSC2 system
Interactive ID interface set up
with SKYCAT
Possible variables found
The revised Landolt cat being
published

14. Conclusions
ESO is waiting for 100% sky coverage before using routinely GSC2 for telescope operations
EIS is GSC2 “best customer” with GSC2 used in ALL EIS Surveys
GSC2 accuracy well within the requirements
GSC2 is valuable support for FLAMES users
GSC2 used to set a new astrometric standard for Landolt stars --> important for pipeline photometric calibrations ... not only EIS but also VLT