CLASS 40 GHz 2016 - 2022 Observations (DR1)

Polarization Sky Masks

Coordinate System:
Projection Type:
HEALPix, ring, Nside=128
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CLASS DR1 diffuse sky masks were defined to mask sequentially larger regions with the brightest polarized synchrotron (sX) or dust (dX) emission, where X is an integer 0 − 9.The sX and dX masks exclude regions of polarized intensity based on the 2018 (PR3) Planck Commander synchrotron and dust component maps, respectively. The smoothing and thresholding algorithm is described in more detail in Eimer et al. (2023). Additionally, all masks exclude data outside of the CLASS survey boundary at declinations δ = −76° and δ = 30°.

A common bright source mask for the CLASS survey region is included in the sX and dX masks. The source mask is based on the Planck PR2 30 and 44 GHz polarized compact source catalog. In cases where sources have angular separation less than 1°, only the brightest source of the collection was kept. Of the remaining catalog, the brightest 70 sources were masked. The source mask has a 3° diameter exclusion region centered at each of the selected points, and custom regions are tailored to surround Tau A and a few extended sources.

All masks are binary: 0=masked (not used); 1=unmasked (used).

Additional Information:

CLASS Data Pipeline and Maps for 40 GHz Observations through 2022, Li et al. (2023)

CLASS Angular Power Spectra and Map-Component Analysis for 40 GHz Observations through 2022, Eimer et al. (2023)

A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Andrew F. Ptak
LAMBDA Director: Dr. Thomas M. Essinger-Hileman
NASA Official: Dr. Thomas M. Essinger-Hileman
Web Curator: Mr. Michael R. Greason