True Universe Output Product

$SetSchemaPath sim/euc-sim-TrueUniverseOutput.xsd

Data product name

$PrintDataProductName

Data product custodian

$PrintDataProductCustodian

Name of the Schema File

$PrintSchemaFilename

Last Edited for DPDD Version

1.1

Processing Elements Creating / Updating / Using the Product

Creators:

  • EuclidTU

Consumers:

  • ComputeFluxes, SimSpectraGenerator

Processing Function using the products

Within PF_SIM, the following PF use this product:

  • SIM_ELViS_Simulator, SIM_TIPS_Simulator, SIM_Imagem, SIM_EXT, SIM_IAL_Pipelines

Here are other PF using this product:

  • PF_VIS, PF_MER, PF_SIR

Proposed for inclusion in EAS/SAS

This product is proposed for inclusion in the SAS: no

This product is mostly for validation use.

Data Product Elements

$PrintDataProductElements

Detailed Description of the Data Product

This data product is produced by the EuclidTU Processing Element. It contains references to star, galaxy and SSO catalogues, spectra files (optional), associated SED libraries, reference filter filenames, and an image thumbnails library (optional). A TrueUniverseOutput lists all the input FITS files that have been used to compute magnitudes and spectra.

The star, galaxy and SSO catalogues described in a TrueUniverseOutput data product result from the spatial merge of several Galaxy Catalog Product and Star Catalog Product according to some magnitude and flux limits specified in a Sim Request Product, or an input configuration product, such as a Vis Input Configuration Product, Nip Input Configuration Product, Nis Input Configuration Product or Ext Input Configuration Product.

The TrueUniverseOutput data product contains the following elements:

  • InputProductId: ProductID of the input configuration product used to produce this true universe output product.

  • EuclidPointingId: PointingId coming from the Reference Survey Observation.

  • ObservationDate: refer to observation date of the images.

  • Pointing: Pointing of the observation.

  • StarCatalogRelease: Specify the catalog type (MAIN, MLT, etc) and a version number. Value is ‘Empty’ if no StarCatalog has been produced

  • StarCatalog: Description of a star catalog: spatial coverage, input SED library and reference filter FITS files, the catalog FITS filename, and the spectra FITS filename. The star catalogue FITS file format is described in Star Catalog Product (optional)

  • GalaxyCatalogRelease: Specify the type of catalog (e.g. WIDE, DEEP) and a version number. Value is ‘Empty’ if no GalaxyCatalog has been produced

  • GalaxyCatalog: Description of a galaxy catalog: spatial coverage, input SED library and reference filter FITS files, the catalog FITS filename, and the spectra FITS filename. The galaxy catalogue FITS file format is described in Galaxy Catalog Product (optional)

  • StampsLibrary: List of FITS files containing galaxy image thumbnails to paste in the simulated images (optional)

  • MagnitudeLimit: Magnitude cut in the Euclid H-band filter in AB system. It applies both to stars and galaxies (optional)

  • MagnitudeLimitFilter: Filter for the magnitude cut in AB system (default: Euclid-H band) (optional)

  • LogHalphaFluxLimit: log(Halpha flux) cut, with Halpha in unit of erg/s/cm2/A (optional)

  • SsoCatalog: Description of a SSO catalog: spatial coverage, start and end date of observation, SED library and reference filter FITS file, the catalog FITS filename. The SSO catalog FITS file format is described in SSO Catalog Product (optional).

The name of the release is given by the DataSetRelease element in the Header section of the data product.

Spectra FITS format

A star or a galaxy catalogue can be distributed with a library of spectra for each source. In this case, an additional SED table HDU is appended at the end of the catalog. This table contains three columns SOURCE_ID, SED_INDEX and SPECTRA_HDU. SPECTRA_HDU points to an extension with name SPECTRA_<id> in the spectra library FITS file. SED_INDEX points to a spectrum in the image contained in this extension.

The spectra are stored in multi-extension FITS files with the format described in Star Catalog Product or Star Catalog Product. A spectra library FITS file contains at least 2 extensions WAVELENGTH and SPECTRA, defining respectively a 1D array of wavelength, and a 2D array of spectra with the dispersion along the first axis, and the spectra ID along the second axis. Spectra IDs start at zero.

Image Thumbnails FITS format

Galaxy image stamps are produced by the SL SWG. They correspond to objects with KIND=4 in the galaxy catalogs. The bulge_r50 value corresponds to the index of the stamp in the stamps library. The stamps are stored in a multi-extension FITS file with the format sim.stampsLibrary 0.1. Each extension contains a stamp, with WCS information.

Star SED Library format

The format of the Star SED library is specified by the FITS format sim.starSedLibrary 0.2. A SED library FITS file contains 2 extensions WAVELENGTH and SED, defining respectively a 1D array of wavelength, and 2D array of SED templates with the dispersion along the first axis, and the SED ID along the second axis. SED IDs start at zero.

Galaxy SED Library format

The format of the Galaxy SED library is specified by the FITS format sim.galaxySEDLibrary 0.2. It combines 3 libraries: 1 for the galaxies, 1 for the QSO and 1 for the High redshift galaxies.

Milky Way extinction model

The MW extinction is modelled with the O’Donnell (1994). This wavelength-dependent extinction model is the linear combination of 2 functions f1, and f2 defined above 1400A.

../../_images/mw_extinction.png