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Spitzer photometry and more. Discussion session goals: Update team & coordinate efforts. Elements involved in discussion. PSFs in all bands (HST & Spitzer) Robust Spitzer Source Extractor photometry catalogs Quantitative structural parameters. Spitzer Mosaics.
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Spitzer photometry and more Discussion session goals: Update team & coordinate efforts
Elements involved in discussion • PSFs in all bands (HST & Spitzer) • Robust Spitzer Source Extractor photometry catalogs • Quantitative structural parameters
Spitzer Mosaics • C.f. update on clashwiki for IRAC • Note: MIPS mosaics not yet staged!
In situ photometry method • Source Extractor • Critical to set detection parameters appropriately, to account for the crowding • E.g. a mexican hat, or simply no convolution kernel works well • Parameters have been vetted, and new catalogs have been generated • Everything is staged online, and notes are on clashwiki
Accounting for crowding • Local • Galfit fitting within IRAC mosaics • Using high-res information • TFIT (though not using this) • IvoPhot (unresolved-convolution-based) • Python galaxy fitting (pygfit) (uses full resolution structural information)
pygfit • Produces “clean” photometry and uncertainties from crowded low-resolution mosaics • Paper submitted to PASP. • See http://www.baryons.org/pygfit/ for • paper, • full code including an example, and full simulation suite • cookbook • In process of applying it to CLASH • Spitzer PSFs and good IRAC mosaic rms images are critical, testing underway • Need person power! • Leonardo+others at STScI? • Other CLASH team members?
HST PSFs Needed for high-resolution structural fits… • Methodology • List of unresolved sources • PSFEx • Target & band • Individual FLT files vs mosaics • Parallel efforts • Coe • Alberto • Leonardo+ • John • Others? • We need to organize all efforts on the archive, systematically!
Spitzer PSFs • Handbook PSFs – but orientation and AOR details an issue • Using the HST-determined unresolved source list • > empirical PSFs for Channel 1 and 2 for all fields • Other? PSFEx? Handbook + AOR processed?... • C.f. clashwiki update
GALAPAGOS/Galfit/dimage status • Ulli; goal: HST structure • 1206, F814W • 1206 flanking fields, F814W • 2248, F814W in progress • Amata; goal: Subaru structure, calibrate via HST overlap • A383, F814W • 1206, F814W • 0416, F814W • Leonardo; goal: needed to have something to test pygfit • MACS 0329, F606W • John M, dimage; goal: ICL • 1206, F160W
Vetting photometry with SED fitting • See quality analysis plots!