Data Challenge Map Sets 04.YY
Feb 6 2018, Clem Pryke
We have made sets of simulated CMB-S4 fsky 3% maps with bands, resolutions and noise levels as per the CDT report "Science Traceability Matrix" - these are dubbed "experiment definition 04. The specs are repeated on the Experiment Definitions page.
These are combined with the seven foreground models as used in appendix A of the CDT report to form map sets 04.00 through 04.06. What these foreground model are is noted on the Sky Models page. These sets of maps are available on NERSC in directory /project/projectdirs/cmbs4/data_04.00 etc. The intent is have multiple groups or individuals re-analyze these maps to determine the precision with which the tensor-to-scalar ratio can be recovered with a particular algorithm for the given noise levels and foreground behavior.
Here is a plot showing the Q maps for realization 0001 and its components where each column is a frequency band. The top row shows the lensed-LCDM input. The second row is tensors with the color stretch zoomed in by factor 20 (for r=0.01). The third row is the foreground model - in this example one of the PySM variants. The fourth row is the noise component which blows up towards the edge of the field in a way which is typical of small aperture observations where the instantaneous field of view is large compared to the field size. The bottom row is what one actually gets in a real experiment - all of the above added together. Note that a pdf version is available which allows one to zoom in and see the full resolution of the maps.
The plot below shows the seven foreground models in each of the bands. We see that they all roughly agree as to the level of synchrotron but differ strongly in the level of dust emission. The three PySM models based on the same templates and differences between them are subtle. The Flauger/Hensley MHD model shows how the sim box has been manipulated to cover the desired obs region.