Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-09-14
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
12 pages, 12 figures, accepted for publication in the Astrophysical Journal. Simulation data (1000 convergence power spectra a
Scientific paper
Using 1000 ray-tracing simulations for a {\Lambda}-dominated cold dark model in Sato et al. (2009), we study the covariance matrix of cosmic shear correlation functions, which is the standard statistics used in the previous measurements. The shear correlation function of a particular separation angle is affected by Fourier modes over a wide range of multipoles, even beyond a survey area, which complicates the analysis of the covariance matrix. To overcome such obstacles we first construct Gaussian shear simulations from the 1000 realizations, and then use the Gaussian simulations to disentangle the Gaussian covariance contribution to the covariance matrix we measured from the original simulations. We found that an analytical formula of Gaussian covariance overestimates the covariance amplitudes due to an effect of finite survey area. Furthermore, the clean separation of the Gaussian covariance allows to examine the non-Gaussian covariance contributions as a function of separation angles and source redshifts. For upcoming surveys with typical source redshifts of z_s=0.6 and 1.0, the non-Gaussian contribution to the diagonal covariance components at 1 arcminute scales is greater than the Gaussian contribution by a factor of 20 and 10, respectively. Predictions based on the halo model qualitatively well reproduce the simulation results, however show a sizable disagreement in the covariance amplitudes. By combining these simulation results we develop a fitting formula to the covariance matrix for a survey with arbitrary area coverage, taking into account effects of the finiteness of survey area on the Gaussian covariance.
Hamana Takashi
Matsubara Takahiko
Sato Masanori
Takada Masahiro
No associations
LandOfFree
Simulations of Wide-Field Weak Lensing Surveys II: Covariance Matrix of Real Space Correlation Functions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Simulations of Wide-Field Weak Lensing Surveys II: Covariance Matrix of Real Space Correlation Functions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Simulations of Wide-Field Weak Lensing Surveys II: Covariance Matrix of Real Space Correlation Functions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-394929