Cosmological parameters, shear maps and power spectra from CFHTLenS using Bayesian hierarchical inference
| Autor: | Justin Alsing, Andrew H. Jaffe, Alan Heavens |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Particle physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) COSMIC SHEAR PLANCK CMB GALAXY SURVEYS FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astronomy & Astrophysics 01 natural sciences Omega LIKELIHOOD Minimal model symbols.namesake gravitational lensing: weak 0103 physical sciences MICROWAVE BACKGROUND DATA cosmological parameters Planck 010303 astronomy & astrophysics Weak gravitational lensing Photometric redshift Physics methods: statistical Science & Technology 010308 nuclear & particles physics CONSTRAINTS Astronomy and Astrophysics DISCORDANCE Redshift 0201 Astronomical And Space Sciences TELESCOPE LENSING SURVEY Space and Planetary Science Physical Sciences symbols large-scale structure of Universe REDSHIFT DISTRIBUTIONS Neutrino APPROXIMATION Free parameter Astrophysics - Cosmology and Nongalactic Astrophysics |
| Popis: | We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the CFHTLenS weak lensing survey - the first application of this method to data. In the first approach, we sample the joint posterior distribution of the shear maps and power spectra by Gibbs sampling, with minimal model assumptions. In the second approach, we sample the joint posterior of the shear maps and cosmological parameters, providing a new, accurate and principled approach to cosmological parameter inference from cosmic shear data. As a first demonstration on data we perform a 2-bin tomographic analysis to constrain cosmological parameters and investigate the possibility of photometric redshift bias in the CFHTLenS data. Under the baseline $\Lambda$CDM model we constrain $S_8 = \sigma_8(\Omega_\mathrm{m}/0.3)^{0.5} = 0.67 ^{\scriptscriptstyle+ 0.03 }_{\scriptscriptstyle- 0.03 }$ $(68\%)$, consistent with previous CFHTLenS analysis but in tension with Planck. Adding neutrino mass as a free parameter we are able to constrain $\sum m_\nu < 4.6\mathrm{eV}$ (95%) using CFHTLenS data alone. Including a linear redshift dependent photo-$z$ bias $\Delta z = p_2(z - p_1)$, we find $p_1=-0.25 ^{\scriptscriptstyle+ 0.53 }_{\scriptscriptstyle- 0.60 }$ and $p_2 = -0.15 ^{\scriptscriptstyle+ 0.17 }_{\scriptscriptstyle- 0.15 }$, and tension with Planck is only alleviated under very conservative prior assumptions. Neither the non-minimal neutrino mass or photo-$z$ bias models are significantly preferred by the CFHTLenS (2-bin tomography) data. Comment: Matches accepted version |
| Databáze: | OpenAIRE |
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