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Objectives
•Remove Bright EG point sources prior to polynomial EOR FG subtraction
•Issue: Mode-mixing / ‘Frizz’•RTS will Peel some bright sources as part
of CML•It will be possible/necessary to remove
further sources after imaging•Characterize residuals/effect on (the
other) PS
Matched Filters
•Generally; positions, fluxes, spectra unknown
•Matched filter is the optimal linear S/N estimator of source amplitudes
•Peaks in filtered maps used to identify PS€
D(x) = Aτ (x) + N(x)
Aest = ψ (x)D(x)dx 2∫ˆ ψ ∝ ˆ τ /P(k)
Matrix Filters •Extension of Matched Filters to multi-channel •Developed for Planck CMB maps (Herranz et
al. astro-ph/08082884• Incorporates cross-channel correlations but
allows for independent spectral slopes
•Each filtered image estimates source fluxes
€
wl (k) = ψ lm
m
∑ (k)Dm (k)
Matrix Filters• MTXF applied to MAPS +
RTS 8s snapshot• Beam is a single simulated
position-independent point source
• Peak pixel is the inferred position
OOB – oh oh?• Sidelobes will appear from
sources outside of the primary beam
• Can we detect/locate sources in combined maps?
• Use of MWA survey or other (GMRT?) data to locate relevant source?
• What is the accuracy of calibration solution in that direction?
Open Issues / Simulation To-Do:
•Ionosphere•HEALPIX pixelization•Integration, co-addition, registration•Rotation synthesis•Peeling levels and residuals•Calibration / Beam Accuracy•OOB•8 minutes * 200 Channels * 5000 images