Cross-correlation of CFHTLenS galaxy catalogue and Planck CMB lensing using the halo model prescription

A Kuntz - Astronomy & Astrophysics, 2015 - aanda.org
A Kuntz
Astronomy & Astrophysics, 2015aanda.org
Aims. I cross-correlate the galaxy counts from the Canada-France Hawaii Telescope
Lensing Survey (CFHTLenS) galaxy catalogue and cosmic microwave background (CMB)
convergence from the Planck data releases 1 (2013) and 2 (2015). Methods. I improve on an
earlier study by computing an analytic covariance from the halo model, implementing
simulations to validate the theoretically estimated error bars and the reconstruction method,
fitting both a galaxy bias and a cross-correlation amplitude using the joint cross and galaxy …
Aims
I cross-correlate the galaxy counts from the Canada-France Hawaii Telescope Lensing Survey (CFHTLenS) galaxy catalogue and cosmic microwave background (CMB) convergence from the Planck data releases 1 (2013) and 2 (2015).
Methods
I improve on an earlier study by computing an analytic covariance from the halo model, implementing simulations to validate the theoretically estimated error bars and the reconstruction method, fitting both a galaxy bias and a cross-correlation amplitude using the joint cross and galaxy auto-correlation, and performing a series of null tests.
Results
Using a Bayesian analysis, I find a galaxy bias b = 0.92-0.02+0.02 and a cross-correlation amplitude A = 0.85-0.16+0.15 for the 2015 release, whereas for the 2013 release, I find b = 0.93-0.02+0.02 and A = 1.05-0.15+0.15.
Conclusions
I thus confirm the difference between the two releases found earlier, although both values of the amplitude now appear to be compatible with the fiducial value A = 1.
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