SPT

South Pole Telescope

Product Name
Fourier-Space Beam Functions for the 2008 Season
Mission
SPT

Description

These files contain one-dimensional azimuthally quadrature-averaged, Fourier-domain beam functions for South Pole Telescope (SPT) observations during the 2008 season for the 150 GHz and 220 GHz bands, produced for the first SPT data release in December 2011.

The one-dimensional averages were computed from the Fourier transforms of the two-dimensional real-space beams. For details on the beam estimation procedure, see the documentation for those files.

The one-dimensional, Fourier-domain beam profiles are normalized to 1 at multipole moment l=800. Estimates of 7 contributions to the beam uncertainty are included in additional columns. Brief descriptions of each source of uncertainty and the manner in which it is estimated follow.

Source 1 (column 3) Uncertainty due to potential variation in detector time constants in the low-elevation Venus observations, estimated by measuring the change in B(l) obtained using different radii to stitch together the inner beam (measured with bright sources in the maps) and outer beam (measured with Jupiter).
Source 2 (column 4) Uncertainty due to potential focus variations during the low-elevation Venus observations, estimated by measuring the change in B(l) obtained by adding a constant value, (0.05% of the beam maximum), to the inner beam.
Source 3 (column 5) Uncertainty due to variations in observing conditions over time or elevation, estimated by measuring the scatter in B(l) obtained using different bright point sources to measure the beam.
Source 4 (column 6) Uncertainty due to potential gain differences in the Jupiter and Venus maps, estimated by measuring the change in B(l) obtained using a different integration region for the calculation of the relative scaling of the Jupiter and Venus beam maps.
Source 5 (column 7) Uncertainty due to any residual scan-synchronous signal present in the maps, estimated using the change in B(l) obtained when an algorithm to remove scan-synchronous signal is turned on and off.
Source 6 (column 8) Uncertainty due to residual atmospheric noise in the low-elevation Venus observations, estimated by measuring the scatter in B(l) obtained using independent individual observations of Venus.
Source 7 (column 9) Uncertainty due to potential electrical cross-talk between detectors on the same readout channel, estimated by measuring the change in B(l) when an algorithm to correct for this potential cross-talk is turned on and off.

A complete description of the observations, data processing, calibration, instrument response, and mapmaking process for this data release is in Schaffer et al. 2011, ApJ, 743, 90.

Back to Product Page

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. Alan P. Smale
LAMBDA Director: Dr. David T. Chuss
NASA Official: Dr. David T. Chuss
Web Curator: Mr. Michael R. Greason