Tuesday, January 10, 2012

1201.1803 (M. Shimon et al.)

Constraints on the Neutrino Mass from SZ Surveys    [PDF]

M. Shimon, Y. Rephaeli, N. Itzhaki
Statistical measures of galaxy clusters are sensitive to neutrino masses in the sub-eV range. We explore the possibility of using cluster number counts from the ongoing PLANCK/SZ and future cosmic-variance-limited surveys to constrain neutrino masses from CMB data alone. The precision with which the total neutrino mass can be determined from SZ number counts is limited mostly by uncertainties in the clusters mass function; these are explicitly accounted for in our forecast. We find that projected results from the PLANCK/SZ survey can be used to determine the total neutrino mass with a ($1\sigma$) uncertainty of 0.08-0.11 eV, assuming fiducial neutrino mass in the range 0.1-0.3 eV, if the survey detection limit is set at the $5\sigma$ significance level. This improves on the limits expected from PLANCK/CMB lensing measurements by a factor 1.5-2. With a cosmic-variance-limited SZ survey we obtain ($1\sigma$) uncertainty of 0.05-0.07 eV. Combined PLANCK and the X-ray RASS cluster catalogs could constrain $M_{\nu}$ at the 0.04 and 0.07, assuming fiducial neutrino masses 0.1 and 0.3 eV, respectively. A few percent uncertainty in the mass function parameters could result in a factor of up to $\sim 50%$ degradation of our PLANCK, CVL and PLANCK+RASS forecasts. The latter two, which significantly benefit from cluster surveys, are more prone to mass function uncertainty. This degradation becomes less significant for neutrino masses 0.3 eV or higher. This highlights the relevance of mass function uncertainties for cosmological parameter estimation. Our analysis shows that if the (total) neutrino mass is close to the lower limits deduced from neutrino oscillation experiments, cluster number counts provide a viable complimentary cosmological probe to CMB lensing constraints on $M_{\nu}$.
View original: http://arxiv.org/abs/1201.1803

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