## WMAP |
## Wilkinson Microwave Anisotropy ProbeThe data made available through this page has been updated. The most recent version of this data may be accessed through /product/map/current/ Product Name
Sky Maps
Mission
WMAP
Coord. System
Galactic
Projection Type
HEALPix, nested
Resolution
0.23
^{°}- 0.93^{°} (frequency dependent)Description WMAP maps of the sky are supplied in FITS files, with the maps contained within binary table
extensions. The maps are stored in a nested HEALPix projection and are supplied at three resolutions: WMAP's standard Res 9
(N Iterative algorithms are used to create skymaps from the calibrated differential time-ordered WMAP data for each of the ten differencing assemblies. Each pixel in a map represents a sky temperature for the bandpass appropriate to the differencing assembly. The CMB dipole has been removed from the Stokes I maps. Maps for seven years of WMAP data have been supplied to LAMBDA. Full seven year maps
were produced by performing a weighted, pixel-by-pixel, mean of the seven single year maps;
the N The maps of the individual differencing assemblies of a single frequency band (Q1 and Q2; V1 and V2; W1, W2, W3, and W4) have been combined to produce coadded maps for each frequency band. Many of the files that contain polarization maps also contain an extension containing
the polarization noise covariance matrices for the maps. See the
detailed description mentioned above
for formatting details. While available for the Res 4 maps, these matrices do not fully
characterize the pixel-to-pixel noise in these maps. Therefore a more accurate and much
larger inverse covariance (or N Pixel noise in units of mK may be evaluated from N
Foreground reduced maps have been produced by removing a foreground model from the 'unreduced' maps using the Foreground Template Model discussed in Hinshaw, et.al., 2006 and Page, et.al, 2006; see those papers for details. Briefly, synchrotron, free-free, and dust emission templates were modeled and then subtracted from the single year 'unreduced' maps. The goal was to produce a set of maps with the foreground removed while retaining WMAP's noise characteristics. Because the K maps were used to produce the foreground models, only Ka, Q, V, and W band foreground reduced maps were created and delivered to LAMBDA. In some cases, Ka was also used in the foreground model; in those cases, the Ka Stokes I maps have been zeroed out. As with the 'unreduced' maps, full seven year maps were produced by performing a
weighted, pixel-by-pixel, mean of the seven single year maps; the N The same foreground template model was used to produce foreground reduced high resolution (res 10) V and W maps. The low resolution (res 4, N ## Version V4P1When the multi-year, multi D/A, reduced resolution maps are formed, full inverse covariance matrix weights are employed in the averaging. Thus the non-cleaned co-added maps have been recomputed with the new matrices. The previous, V4P0, maps were correctly characterized by the V4P0 covariance matrices, but the new maps and matrices more fully capture our knowledge of the instrument and data. Please note that only the Stokes Q and U maps without foreground cleaning were affected. ## Additional Information |