The Awe photometric pipeline Software implementation Photometric pipeline

The Awe photometric pipeline Software implementation

Photometric pipeline : class model Cal 569 Cal 565 Cal 563/Cal 564 Cal 562

Photometric pipeline : equation to solve

Photometric pipeline : source catalogs Phot. Src. Catalog : association between standard star catalog and Sextractor catalog photsrccat. refcat = Phot. Ref. Catalog() photsrccat. frame = Science. Frame() photsrccat. transform = Phot. Transformation() photsrccat. make() rawzero = photsrccat. photsourcelist[3]. get_raw_zeropoint() rawzero_list = photsrccat. get_list_of_raw_zeropoints()

Photometric pipeline : color terms Color terms are dealt with in photsrccatalog. make() photsrccatalog. transform = Phot. Transformation() transf. get_dict_of_transformed_magnitudes(mag_id, refcat) the mag_id is the primary key through which the system identifies the photometric band Examples : Johnson. V, Cousins. R, Sloan. U, Sloan. G

Photometric pipeline : extinction Atmospheric extinction is treated as a pluggable algorithm three different algorithms implemented at present atmospheric_extinction = Atmospheric. Extinction. Frames() atmospheric_extinction. polar = photsrccat_list_1 atmospheric_extinction. equat = photsrccat_list_2 atmospheric_extinction. extcurve = Phot. Extinction. Curve() atmospheric_extinction. make() system easily extended with new ways to derive the atmospheric extinction

Photometric pipeline : zeropoints The zeropoints are derived by and contained within a Photometric. Parameters object. photometricparameters. photcat = photsrccatalog photometricparameters. extinct = atmospheric_extinction photometricparameters. make() a Photometric. Parameters object represents the Calfile that is used in the image pipeline

Photometric pipeline : illumination correction • software has to be implemented • current scheme is to apply the correction on frame level in the image pipeline • the input frames for the photometric pipeline are, therefore, already corrected for this effect

Photometric pipeline : a general recipe photsrccatalog. refcat = Phot. Ref. Catalog() photsrccatalog. frame = Science. Frame() photsrccatalog. transform = Phot. Transformation() photsrccatalog. make() atmospheric_extinction = Base. Atmospheric. Extinction() atmospheric_extinction. make() photometricparameters. extinct = atmospheric_extinction photometricparameters. photcat = photsrccatalog photometricparameters. make()

Photometric pipeline : a use case (1) Available resources for (rough) photometric calibration : • during the night, for every filter only ONE observation was made of a standard field • standard stars are present on only ONE of the chips of the N-chip camera • a standard extinction curve has to be used • no illumination correction is known, nor can it be derived Conclusion : the prospects are bleak

Photometric pipeline : a use case (2) the_photsrccatalog. refcat = Phot. Ref. Catalog() the_photsrccatalog. frame = Science. Frame() the_photsrccatalog. transform = Phot. Transformation() the_photsrccatalog. make() photsrccatalog. frame = Science. Frame() photsrccatalog. set_sky_background()

Photometric pipeline : a use case (3) atmos_extinction = Atmospheric. Extinction. Curve() atmos_extinction. filter = scienceframe. filter atmos_extinction. extcurve = Phot. Extinction. Curve() atmos_extinction. report = Photometric. Extinction. Report() atmos_extinction. make() Note the dependency on a Filter object Note the dependency on a Photometric. Extinction. Report object

Photometric pipeline : a use case (4) the_photometricparameters = Photometric. Parameters() the_photometricparameters. photcat = the_photsrccatalog the_photometricparameters. extinct = atmos_extinction the_photometricparameters. make() photometricparameters. photcat = photsrccatalog photometricparameters. extinct = atmos_extinction photometricparameters. set_zeropoint(zp, zp_err)

Photometric pipeline : resources • • /cvsroot/catalog/ /cvsroot/opipe/Toolbox/photometry /cvsroot/opipe/docs /cvsroot/opipe/astro/main • Yours truly (ronald@astro. rug. nl)