CALPRODUCT-NS-002: NISP-S Absolute Photometric Standards¶
Parent requirement¶
Scheduling¶
Once, during PV phase.
Time-critical¶
no
Objective¶
Obtain absolute flux standard measurements as a function of position for each NISP detector.
The absolute zeropoint is determined during PV phase, and subsequent monitoring of relative fluxes in the Self-cal field provide the total throughput at any point of time.
If photometric standard stars are available in the Self-cal field, then the absolute throughput could be monitored with the Self-cal data alone. Currently, candidate spectro-photometric standards are available, but the HST observations required for confirmation and determining their true SEDs have not yet been obtained.
Fulfilled by¶
Targets and pointing constraints¶
Pointing: Must check that the 1st and 0th order of the standard does not overlap with those of other sources. This can tightly constrain the times at which a particular grism can be calibrated.
# ID |
R.A. |
Dec |
Type |
J [AB mag] |
H [AB mag] |
comment |
GRW+70 |
13:38:49.21 |
+70:17:07.25 |
DA2.4 |
14.1 |
14.7 |
ICRS 2016.0; pmra=402.079 pmdec=-24.556 |
GD153 |
12:57:02.32 |
+22:01:52.63 |
DA1.2 |
14.9 |
15.6 |
|
GD71 |
05:52:27.62 |
+15:53:13.23 |
DA1.5 |
14.6 |
15.3 |
DO NOT USE; crowded |
WD1057+719 |
11:00:34.24 |
+71:38:02.92 |
DA1.2 |
15.4 |
17.0 |
DO NOT USE; crowded |
KF06T2 |
17:58:37.99 |
+66:46:52.11 |
K1.5III |
12.8 |
12.5 |
DO NOT USE; crowded; too bright |
Data volume¶
672960 MB (480 executions of the ROS_D1)
Processing input¶
Ground Processing Input Data: All calibration products to run the standard science pipeline (BPM, darks, flat, nonlinearity etc), reference measurement of standard star, RSR curves (relative spectral response of the system (mirrors, optics, instrument)
Data Description:
Processing output¶
spectrophotometric response curve, plots of flux measurements as a function of position, first/second exposure, detector etc.
Required accuracy, constraints¶
spectrophotometric flux measurement / response curve derived from each position shows no >x sigma deviation from mean, flux measurements of first compared to second exposure don’t show trend, response curve is reasonably close to what is expected
Processing tools¶
L1 science pipeline and absolute calibration pipeline, additional offline trend analysis of flux measurements
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
NISP-S calibration scientist