Cosmology and Galaxies Level 3 Requirements Collated by Richard McMahon and Joe Mohr 2016, June 24th LSST@Europe2, Belgrade

L3 requirements Ability to rerun source detection with different background estimators Motivation: Photometry in central regions of clusters Detection of inter-cluster light Extended emission around large galaxies e.g. tidal tails Large resolved galaxies May need to be able to ’add sky that was subtracted’ back into L2 coadd images A residual image might be a useful product i.e. coadd–model based on the catalogue parameters 2016, June 24th LSST@Europe2, Belgrade

L3 requirements Ability to rerun source detection with a different kernel or deblending parameter or other catalogue software tunable parameters Motivation: To investigate effects and also some science cases maybe require non- standard parameters Detection of inter-cluster light Extended emission around large galaxies e.g. tidal tails May need to be able to ’add sky that was subtracted’ back into L2 coadd images A residual image might be a useful product i.e. coadd–model based on the catalogue parameters 2016, June 24th LSST@Europe2, Belgrade

L3 Requirements Next steps Access to L2 products of LSST-like L2 data simulated products; coadd images, ancillary products (psf, weight maps, masks etc) and catalogues Acess to L2 products of LSST-like L2 real data like Subaru HSC data processed by LSST DM pipeline 2016, June 24th LSST@Europe2, Belgrade