CALBLOCK-F-003: Completeness and Purity Calibration (CPC)¶
Observation configuration file¶
Not applicable
Scheduling¶
Planning and replanning by EC-SURV.
Grism ratio and completion: The final blue:red grism ratio is 25:15. A single pass shall always use the same grism. As a goal, a strong imbalance between blue and red data should be avoided toward the data releases. However, technical constraints and space weather may interfere with this goal.
Zodi corrections: The total number of passes, and the exposure-time ratio of 25:15, may require smaller corrections because of the actual zodiacal background at these fields. Corrections are at the discretion of EC-SURV.
Data sharing between EDFs and CPCs: The EDF-N, EDF-S, CPC-N, and CPC-S share the same sky areas, and the same blue:red exposure-time ratio. A deep observation therefore contributes toward completing the CPC, and vice versa.
Time-critical¶
No.
Objective¶
Generate a spectroscopic sub-sample of at least 120,000 galaxies with 99% purity. The galaxies must be selected with the same selection criteria than in the wide survey. Estimates of the number density of galaxies imply a survey area of at least 40 square degrees.
Observations¶
The completeness and purity calibration (CPC) is obtained from the EDF-N and the EDF-S, together totaling 43 square deg. The main objective is to observe these fields with sufficiently many orientations such that the slitless spectra can be optimally decontaminated.
Each field requires 10 visits that have their own reference angle depending on scheduling, with a minimum separation angle of 5 degrees. In addition, the K-sequence introduces 4 different angles for the red grisms. The blue gris does not have a requirement on angle separation.
Blue grism: The exposure time ratio is blue:red = 25:15, to account for different zodi background, and the reduced number of photons per flux per wavelength interval in the blue grism compared to the red grism.
VIS Cycling: The VIS ROS-inline calibrations follow the nominal wide-survey cycling, as described in ROS: inline VIS calibrations and cadences.
Fulfilling¶
CALPRODUCT-NS-010: Completeness and Purity Calibration (CPC) (REPLACED)
CALPRODUCT-VS-015: VIS Noise Bias Calibration Fields (REPLACED) (partially)
Targets and pointing constraints¶
Pointing: The red passes of the CPC fields must be scheduled at specific times to maintain the requirements on number of angles, and angle separation.
# ID |
R.A. |
Dec |
CPC-N |
269.733 |
+66.018 |
CPC-S |
61.241 |
-48.423 |
Instrument configuration¶
Instrument: Wide survey
Methodology / Uplink procedure¶
Entity: VIS and NISP
Commanding Method:
Dither Sequence: Within a single pass, execute the ROS at each grid point.
Inter-operability constraints¶
None
In-orbit duration¶
In-orbit Duration:
Processing input¶
Ground Processing Input Data:
Data Description:
Processing tools¶
Standard wide survey processing.
L3 PFs: SELID, VMSP.
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
Calibration Lead