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Table 2

Summary of the algorithms compared in the SZ Challenge.

Method Shape matching CPU Patches Number of PS subtraction FG subtraction Main characteristics
time (h) (size deg.) patches method method

MMF1 Yes 50–60 14.6°×14.6° 640 Best yield among MMFs
Good photometry
MMF2 Yes 31 14.6°×14.6° 371 Good yield
Good photometry
MMF3 Yes 5 10°×10° 504 mask 10σ PS Good yield
Good photometry
MMF4 Yes full sky Poor yield (see Sect. 3.1.4)
No photometry
PwS Yes 5.73 14.6°×14.6° 2064 Good yield
Good photometry
BNP No 15 10°×10° 512 MHW Subtract 857 Median yield
Poor photometry
ILC1 Yes 2–3 see caption (504) Good yield
Good photometry
ILC2 No 2–3 see caption (504) Best yield among ILCs
Good photometry
ILC3 Yes 24 full sky Template fitting Poor yield
Good photometry
ILC4 Yesa 6 10°×10° 504 mask 10σ PS Good yield
Good photometry
ILC5 No 0.2 11°×11° 461 SExt. Poor yield (see Sect. 3.3.5)
Poor photometry
GMCA No 4 10°×10° 504 Median yield
Good photometry

Notes. The first column shows the name of the method. The second column indicates when the code is using a prior on the SZ cluster shape. The uperscript a indicate that the detection did not use a shape prior but that the computation of the SZ flux did. The third column gives the performance in terms of CPU hours needed to complete the analysis. The fourth and fifth column show whether the analysis was made using all-sky maps or projected patches, their area in square degrees and the number of patches. Methods ILC1 and ILC2 work with full sky maps for producing an SZ map (by ILC on needlet coefficients) and then work with 504 small patches for cluster detection by matched filtering (ILC1) or using SExtractor (ILC2). The sixth and seventh columns provide information about any specific method used for subtracting point sources (PS) and Galactic foregrounds (FG). Note that both the MMF and the ILC methods have a built-in way for subtracting both point sources and diffuse foregrounds, by treating them as additional noise (of astrophysical origin) correlated across the channels. Note, also, that the study is made only on clusters at  |b| > 20 degrees Galactic latitude for all methods. The eighth column summarizes the main characteritics of each algorithm in terms of yield at 90% purity and photometric accuracy.

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