South Pole Telescope (SPT)

Binned Bispectrum Measurements

This page provides data products associated with the SPT measurement of the millimeter-wavelength angular bispectrum described in Crawford et al (2013). The bispectrum is recorded in mode triplet bins centered at [l1,l2,l3] of width delta(l)=200. Measurements are presented in three observing bands centered at 95, 150, and 220 GHz and with three levels of galaxy cluster masking: no clusters masked, clusters above M200(rho_crit)=8e14 Msun/h masked, and clusters above M200(rho_crit)=3e14 Msun/h masked.

For use in fitting the measured bispectrum to models, we also provide the theoretical predictions for the thermal SZ bispectrum at 150 GHz (one template for each of the three levels of cluster masking) and the beam realizations used in constructing the systematic covariance matrix. We also present the statistical-only, systematic-only, and statistical-plus-systematic parameter covariance matrices for each level of cluster masking.

These files contain the bispectrum measurements and associated covariance matrices (statistical only) at 95, 150, and 220 GHz from 2008+2009 observations. The bispectrum bins have width delta(l)=200 in all three dimensions and cover the angular frequency range 300 < l < 11000. The bispectrum is assumed to have no covariance between bins, but we do include covariance in a given bin between observing bands. The bispectrum and covariance are reported for three different levels of cluster masking (no clusters masked, clusters above M200(rho_crit)=8e14 Msun/h masked, and clusters above M200(rho_crit)=3e14 Msun/h masked).

The bispectrum values and covariances for each level of cluster masking are in a single ascii file. For each bispectrum bin (a total of 15,670 bins with nonzero weight), the file contains the center l value for each of the three sides of the (l1,l2,l3) triangles in that bin, the value of bispectrum (in units of uK_cmb3) at 95, 150, and 220 GHz, and the elements of the 3x3 band-band covariance matrix (in units of uK_cmb6) for that bin.

The measured bispectrum for no cluster cut is here.

The measured bispectrum for clusters cut above M200(rho_crit)=8e14 Msun/h is here.

The measured bispectrum for clusters cut above M200(rho_crit)=3e14 Msun/h is here.

Additional Details:

  • The information on this page is taken from this SPT page.
  • Crawford et al. 2013, A measurement of the secondary-CMB and millimeter-wave-foreground bispectrum using
    800 square degrees of South Pole Telescope dat", astro-ph/1303.3535

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