########################################## # version history: # # v1.2, created 07Oct2011, added files that # were mistakenly missing: # camb/inidriver.F90 # source/cmbdata.F90 # source/driver.F90 # # v1.1, created 27Sep2011, RK. ########################################## === OVERVIEW === This README documents the version of cosmoMC/CAMB (see http://cosmologist.info/cosmomc and http://camb.info/) that has been modified to interface with the CMB data presented in the SPT paper, "A Measurement of the Damping Tail of the Cosmic Microwave Background Power Spectrum with the South Pole Telescope", Keisler et al, 2011 ("K11"). For this release we begin with the August 2011 version of cosmoMC (which uses July 2011 CAMB) and add some fairly simple modifications: - Add the SPT K11 data, 150 GHz bandpowers spanning ell=[650,3000]. - Add three parameters that control the amplitude of three foregrounds in the SPT 150 GHz data (SZ, Poisson point source power, clustered point source power). - Allow for effective number of neutrinos ("nnu" or "Neff") that are significantly different from 3.046. - Allow for the primordial helium abundance to be free. - Allow for the effect of gravitational lensing on the CMB to be free (CL_phi_phi is rescaled with the A_L ("alens") parameter, which is normally equal to one). - Include improved H_0 measurement from Riess et al, astro-ph/1103.2976. === CONSISTENCY WITH K11 RESULTS === The original likelihood code that was used in K11 was modified version of the May 2010 version of cosmoMC (which used the January 2010 version of CAMB). The new likelihood code (the one in this release) uses the August 2011 version of cosmoMC (which uses July 2011 version of CAMB). We find that while the two codes do not give numerically identical CMB spectra nor Markov chains, the differences are small compared to the uncertainty in the cosmological parameters. The largest differences are for omegach2 (new code lower by 0.00069 = 0.14-sigma in baseline K11 LCDM model) and sigma8 (new code lower by 0.0076 = 0.32-sigma in baseline K11 LCDM model). === OTHER COMMENTS === - Note that three foreground terms should not be included in the TT spectrum given to the WMAP likelihood code. This is the default in the example .ini files. Also note that there is no ASZ parameter for WMAP. We have effectively replaced ASZ by d3000_sz, and implicitly set d3000_sz=0 for WMAP. Including the SZ power in the spectrum given to WMAP would change the WMAP likelihood by a small amount, approximately delta_2lnL_WMAP = 0.1. - By default the three foreground amplitudes have gaussian priors. If you want to turn these priors off, put "use_PS_SZ_prior = F" in your .ini file. - The original K11 likelihood code worked fine with nnu<1.046, although the new likelihood code does not. For this reason we recommend setting 1.047 as the lower limit in free-nnu chains, as shown in the example .ini file "params_neff.ini". The region nnu<1.047 is effectively ruled out anyway using SPT+WMAP, so this lower limit does not affect the parameter constraints. - Please email Ryan at rkeisler@uchicago.edu if you have any questions or comments about this likelihood code or the SPT K11 data. === INSTALLATION === We've provided spt_k11_likelihood_small.tar.gz (1.3 Mb). This contains only the SPT K11 data and those cosmoMC/camb files that were modified. These files should be added to the August 2011 version of cosmoMC (which uses July 2011 CAMB). We cannot guarantee that simply copying these files into your existing cosmoMC directories (e.g. those newer or older than the August 2011 version) will work.