Shear Final Euclidized HST Images product¶

Data product name¶

sheFinalEuclidizedHstImages

Data product custodian¶

SHE

Data model tag¶

8.0

Name of the Schema file¶

ST_DM_Schema/dictionary/pro/she/euc-test-she.xsd

Schema documentation tag¶

Documentation for data product element sheFinalEuclidizedHstImages:

This product contains a set of Euclidized HST images required for calibration of the shear measurement methods.

Documentation for data product element Header:

The generic header of the product.

Data product elements¶

ValidityRange (ins:calibrationValidPeriod)
EuclidizedHstImageCatalogue (sheEuclidizedHstImageCatalogFile)

DataContainer (dss:dataContainer)

EuclidizedHstObjectList (sheEuclidizedHstObject)

sheEuclidizedHstObject 1

DataStorage (dss:dataContainer)

PsfStorage (dss:dataContainer)

sheEuclidizedHstObject 2

DataStorage (dss:dataContainer)

PsfStorage (dss:dataContainer)

…

Processing Element(s) creating/using the data product¶

SHE_HSTCalibration

Processing function using the data product¶

SHE

Detailed description of the data product¶

In its final stage, this product contains a catalogue of postage stamps of galaxies that fulfil a given set of search criteria and which are required for the calibration of the shear measurement methods. The catalogue will provide metadata for these galaxies. It is joined by FITS files of the Euclidized HST postage stamp images of the galaxes themselves and FITS images of the respective PSFs for the galaxy images as derived from the HST exposures.

An intermediate stage provides the full-size FITS images of the reduced HST exposures, each paired with a FITS image of the derived PSFs for these exposures.

In order to produce the final stage products, the reduced HST exposures are supposed to be injected into the OU-EXT AstroWISE database, subsequently processed by existing OU-MER PFs for Euclidization, and finally Euclidized postage stamps are re-extracted using OU-MER’s object detection algorithms on the set of selection criteria.

This way, a set of postage stamp images of galaxies of defined properties is produced which look like they would appear if observed by Euclid, complying with the actual OU-MER selection criteria.

Intermediate calibration algorithms can relate to the full-size HST frames directly, however.

Final Stage Products¶

The catalogue of galaxies for which postage stamps have been requested is provided in a FITS table of the following format:

Parameter name

Fits Data type

Brief description

OBJECT_ID

K

Identifier for the object (TBC)

META_i

TBD

Set of metadata for the object

The FITS output files containing the postage stamp galaxy images are defined as follows:

HDU

Header

Header will contain metadata:

Parameter name	Fits Data type	Brief description
OBJECT_ID	K	Identifier of the Object
SIZE_X	I	x size of postage stamp
SIZE_Y	I	y size of postage stamp
META_i	TBD	Set of metadata for the object

Data

Data will contain an SIZE_X x SIZE_Y image of floats, representing the galaxy image.

The FITS output files containing the PSF images are defined as follows: