Measuring galaxy cluster masses with CMB lensing using a Maximum Likelihood estimator: statistical and systematic error budgets for future experiments
Abstract
We develop a Maximum Likelihood estimator (MLE) to measure the masses of galaxy clusters through the impact of gravitational lensing on the temperature and polarization anisotropies of the cosmic microwave background (CMB). We show that, at low noise levels in temperature, this optimal estimator outperforms the standard quadratic estimator by a factor of two. For polarization, we show that the Stokes Q/U maps can be used instead of the traditional E and Bmode maps without losing information. We test and quantify the bias in the recovered lensing mass for a comprehensive list of potential systematic errors. Using realistic simulations, we examine the cluster mass uncertainties from CMBcluster lensing as a function of an experiment's beam size and noise level. We predict the cluster mass uncertainties will be 3  6% for SPT3G, AdvACT, and Simons Array experiments with 10,000 clusters and less than 1% for the CMBS4 experiment with a sample containing 100,000 clusters. The mass constraints from CMB polarization are very sensitive to the experimental beam size and map noise level: for a factor of three reduction in either the beam size or noise level, the lensing signaltonoise improves by roughly a factor of two.
 Publication:

Journal of Cosmology and Astroparticle Physics
 Pub Date:
 August 2017
 DOI:
 10.1088/14757516/2017/08/030
 arXiv:
 arXiv:1705.00411
 Bibcode:
 2017JCAP...08..030R
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 28 pages, 5 figures: figs 2, 3 updated, references added: accepted for publication in JCAP