Crowded field photometry/astrometry (Example action items: DECam precursor studies of Galactic bulge/plane to estimate the source density as a function of position; Use ImSim pipeline to create synthetic images of crowded fields and test LSST’s astrometry and photometry on resultant CMDs).
Stargalaxy separation (Example action items: HST archival project to generate a point source/extended source truth table; Use of SMASH survey of Magellanic Clouds to empirically benchmark impact of unresolved galaxies on LSB structure mapping; Multi-color deep widefield surveys of known LSB systems to test stargalaxy separation algorithms; Use ImSim input catalog to test stargalaxy separation algorithms).
Photometric metallicity calibration (Example action items: Assemble relevant spectral and photometric datasets. Compare to existing efforts from SDSS, including Ivezic metallicities for FGK stars, and Mann, Lepine and West calibrations for M dwarfs. What are the ranges in mass/color where these relations are valid? Extend these applications to LSST, assuming a LSSTSDSS transformation is robust. Using archival spectra or PanSTARRS data, test how yband photometry can improve the photometric metallicity estimate. How can timeseries information be used to improve metallicity estimates (e.g., Miller, Richards, Bloom et al).
y4 filter calibration (Example action items: Ground based/space based y4 investigations; Can PanSTARRS experience be leveraged for yband calibration? How does varying the water column change the spectral response. SImulate the effect of a varying water column on the y4 filter using existing spectra of FGKM stars.).
Cadence Planning (Example action items: Build the case for Magellanic Clouds cadence; Develop the science and technical case for MW disk and bulge cadence; Develop and test cadence metrics for astrometry).
Stellar variability classification (Example action items: Define classification metrics required for your specific science goals, see example in NearField Cosmology roadmap; Develop light curve classifiers + period finders and test on existing datasets [e.g. LINEAR]; coordinate with Transients science collaboration and tools from EB factory general purpose light curve classifier and intelligent period finder; DECam Bulge survey).
Subgroup specific technical needs (Action items: As defined by individual collaboration members and Working group leads, e.g. photometry of nebulae.).
Theoretical predictions for LSST Milky Way science (Example action items: As defined by individual collaboration members and Working group leads, e.g., simulations that make predictions for LSST; coordinate with Justin Read’s Gaia challenges).
