[to complete] NIR Absolute Photometric Calibration Factors¶
Metadata¶
Data product name |
DpdNirAbsPhotoCalibration |
Data product custodian |
NIR |
Name of the Schema file |
|
Processing Element(s) creating/using the data product |
The DpdNirAbsPhotoCalibration is created by the NIR_AbsolutePhotometry_Pipeline. This pipeline compares “white dwarf” fluxes, extracted in dedicated observations, to derive an inverse sensitivity constant, which can be used to convert from electrons per second (e/s) to microJanskys (μJy). In addition to computing the inverse sensitivity, zero points for converting to AB magnitude and Vega magnitude are provided (ZPAB and ZPVEGA, respectively). Uncertainties are reported for all quantities. The task responsible for the DpdNirAbsPhotoCalibration creation is NIR_ComputeAbsolutePhotometry (under NIR_AbsolutePhotometry project). |
Processing function using the data product |
This is an internal NIR data product, and it is used only by the NIR PF. It is applied by the NIR_ApplyAbsolutePhotometry task (under NIR_AbsolutePhotometry project) inside the NIR_ProcessField_Pipeline. The task writes the inverse sensitivity constant on PHOTFNU keyword. In combination with relative photometric keywords it can be used to convert from native image units to absolute flux, in μJy. flux_in_microJy = PHOTFNU x PHRELDT x PHRELEX x pixel_value The factors contributing to flux_in_microJy are:
set to unity) * pixel_value: The observed flux |
Data Product structure description¶
The main elements inside the Data section are:
Filter: The filter name (e.g. NIR_Y, NIR_J, NIR_H)
ValidityRange: Calibration file validity period estimated
StandardStar: Name of Standard Star used for calibration
CalibrationWavelength: Calibration Wavelength
CentralWavelength: Central Wavelength
HalfPowerBandwidth: Half Power Bandwidth
InverseSensitivity: Inverse Sensitivity
VegaMagnitude: Vega Magnitude