.. _NIRAbsPhotoCalibration: [to complete] NIR Absolute Photometric Calibration Factors ============================================================== Metadata ______________________ +------------------------------------------------+----------------------------------------------------------------------------------------------+ | Data product name | DpdNirAbsPhotoCalibration | +------------------------------------------------+----------------------------------------------------------------------------------------------+ | Data product custodian | NIR | +------------------------------------------------+----------------------------------------------------------------------------------------------+ | Name of the Schema file | .. raw:: html | | | | | | `euc-nir-AbsPhotoCalibration.xsd `_ | +------------------------------------------------+----------------------------------------------------------------------------------------------+ | Processing Element(s) creating/using the data | The **DpdNirAbsPhotoCalibration** is created by the *NIR_AbsolutePhotometry_Pipeline*. | | product | | | | 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: | | | | | | * **PHOTFNU**: The inverse sensitivity from **DpdNirAbsPhotoCalibration** | | | * **PHRELDT**: The relative offset by detector from **DpdNirRelPhotoDetCalibration** | | | * **PHRELEX**: The relative offset by exposure from **DpdNirRelPhotoExpCalibration** (Q1: | | | set to unity) | | | * **pixel_value**: The observed flux | +------------------------------------------------+----------------------------------------------------------------------------------------------+ Data Product structure description ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. DataProductDescrStart 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 .. DataProductDescrEnd .. DetailedDescEnd