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Calibrations

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Please find more on Baseline Calibrations on the NIR instruments resources.


Recommended GCAL configurations and Exp. Times for F2 calibrations:
Quartz Halogen flats and Ar Arcs


Note the following:


GCALflats

All GCALflats are taken with:

  • GCALdiffuser=IR
  • Calibration Lamp = IR greybody - high

Two type of flats are taken:



The following table shows the optimal configuration (exposure time and the GCAL internal ND filter) in order to achieve a ~17 kADU flat field for each filter used in imaging mode.

GCALflat configurations for Imaging
Filter GCAL Filter Calibration Shutter Exp. Time (sec)
J-low ND4.0 Open 3
J-low ND4.0 Closed 3
J ND4.5 Open 60
J ND4.5 Closed 60
H ND4.5 Open 3
H ND4.5 Closed 3
Ks ND2.0 Closed 3
K-blue ND2.0 Open 6
K-red ND2.0 Open 6



The table below shows the optimal configuration (exposure time and GCAL internal ND filter)  for every combination of Grism + filter + Sliit width in order to produce a reliable spectroscopic flat.

GCALflat configurations for Longslit or MOS
GRISMs: JH (R1200) HK (R1200) R3000
Grism + Filter Slit width (pixel) GCAL filter Exp. Time (sec) Plots
JH (R1200) + JH 1 ND2.0 15
JH (R1200) + JH 2 ND2.0 8 plot
JH (R1200)+ JH 3 ND2.0 5
JH (R1200) + JH 4 ND2.0 4   plot
JH (R1200) + JH 6 ND2.0 3
JH (R1200) + JH 8 ND2.0 2   plot
HK (R1200) + HK 1 ND4.5 90
HK (R1200) + HK 2 ND4.5 90   plot
HK (R1200)+ HK 3 ND4.5 75
HK (R1200) + HK 4 ND4.5 60   plot
HK (R1200) + HK 6 ND4.5 40
HK (R1200) + HK 8 ND4.5 30   plot
R3000 + J-low 1 Clear 56
R3000 + J-low 2 Clear 24
R3000 + J-low 3 Clear 16
R3000 + J-low 4 Clear 12
R3000 + J-low 6 Clear 9
R3000 + J-low 8 Clear 6
R3000 + J 1 Clear 10
R3000 + J 2 Clear 5
R3000 + J 3 ND1.0 25
R3000 + J 4 ND1.0 20
R3000 + J 6 ND1.0 12
R3000 + J 8 ND1.0 10
R3000 + H 1 ND1.0 6
R3000 + H 2 ND2.0 50   plot
R3000 + H 3 ND2.0 40
R3000 + H 4 ND2.0 25
R3000 + H 6 ND2.0 20
R3000 + H 8 ND2.0 15
R3000 + Ks 1 ND2.0 32
R3000 + Ks 2 ND2.0 16   plot
R3000 + Ks 3 ND2.0 12
R3000 + Ks 4 ND2.0 9
R3000 + Ks 6 ND2.0 6
R3000 + Ks 8 ND2.0 4


GCAL Ar Comparison Lamps

All arcs are taken with the following configuration of GCAL:

  • GCALlamp=Ar
  • GCALdiffuser=IR
  • GCALfilter = NIR balance
  • Calibration Shutter = Closed (refers to GCAL flat source)

Next table shows the optimal exposure time for each combination of Grism + Filter + Slit width in order to produce a reliable arc.

GCAL Ar configurations for Longslit or MOS
GRISMs: JH (R1200) HK (R1200) R3000
Grism + Filter Slit width (pixel) GCAL filter Exp. Time (sec)
JH (R1200) + JH 1 NIR balance 32
JH (R1200) + JH 2 NIR balance 18
JH (R1200)+ JH 3 NIR balance 12
JH (R1200) + JH 4 NIR balance 10
JH (R1200) + JH 6 NIR balance 8
JH (R1200) + JH 6 NIR balance 8
HK (R1200) + HK 1 NIR balance 90
HK (R1200) + HK 2 NIR balance 60
HK (R1200)+ HK 3 NIR balance 45
HK (R1200) + HK 4 NIR balance 40
HK (R1200) + HK 6 NIR balance 30
HK (R1200) + HK 8 NIR balance 20
R3000 + J-low 1 NIR balance 90
R3000 + J-low 2 NIR balance 90
R3000 + J-low 3 NIR balance 90
R3000 + J-low 4 NIR balance 90
R3000 + J-low 6 NIR balance 90
R3000 + J-low 8 NIR balance 60
R3000 + J 1 NIR balance 60
R3000 + J 2 NIR balance 60
R3000 + J 3 NIR balance 30
R3000 + J 4 NIR balance 30
R3000 + J 6 NIR balance 15
R3000 + J 8 NIR balance 15
R3000 + H 1 NIR balance 180
R3000 + H 2 NIR balance 180
R3000 + H 3 NIR balance 180
R3000 + H 4 NIR balance 80
R3000 + H 6 NIR balance 80
R3000 + H 8 NIR balance 80
R3000 + Ks 1 NIR balance 180
R3000 + Ks 2 NIR balance 180
R3000 + Ks 3 NIR balance 180
R3000 + Ks 4 NIR balance 80
R3000 + Ks 6 NIR balance 80
R3000 + Ks 8 NIR balance 80