Checking PySM maps

From CMB-S4 wiki
Jump to: navigation, search

May 8 2017, Clem Pryke

Julian placed some PySM maps on NERSC in /project/projectdirs/cmb/data/generic/galactic/pysm. We have been using the files pysm_a1d1f1s1_SOS4_030_map_0512.fits etc. These are supposed to contain coadded foregrounds (dust+sync+ame+freefree) generated according to the PySM paper. There is the base model a1d1f1s1 plus a variant a2d4f1s3 - these have been used to make the sim sets 01.01 and 01.02. In 01.01 sim input maps - first try I took a quick look at the maps and spectra derived from a1d1f1s1 155GHz. However, I had not looked at the other frequencies or a2d4f1s3 files - just blindly used them.

As I understand it PySM is supposed to be "Planck locked" at large angular scales where Planck has measured the real sky with decent signal-to-noise. So we can compare to Planck 2015 paper I where in fig8 they show Q/U maps for all 7 polarized bands. (Also see Planck archive where the same maps can be seen by clicking on the pol band links.]

Below are three plots showing the a1d1f1s1 and a2d4f1s3 maps from NERSC and the Planck maps as processed through the same code. Note that while a1d1f1s1 looks very much like Planck as expected, for a2d4f1s3 it looks like the Q/U maps are transposed at higher frequency. At lower frequencies instead of more power (from AME) there seems to be less?

[Note added May 9 2017: Ben Thorne confirms that the Q/U got swapped and the sync is not present in a2d4f1s3 - he is re-generating.]

20170508 fig1.gif 20170508 fig2.gif 20170508 fig3.gif