منابع مشابه
Cosmic Shear and Power Spectrum Normalization with the Hubble Space Telescope
Weak lensing by large-scale structure provides a direct measurement of matter fluctuations in the universe. We report a measurement of this ‘cosmic shear’ based on 271 WFPC2 archival images from the Hubble Space Telescope Medium Deep Survey (MDS). Our measurement method and treatment of systematic effects were discussed in an earlier paper. We measure the shear variance on scales ranging from 0...
متن کاملPower spectrum from weak-shear data
We demonstrate that the aperture mass as a measure for cosmic shear closely approximates (to better than ≈ 5%) the scaled and shifted power spectrum of the projected mass density. This cosmological weak-lensing information can thus be used to directly infer the projected matter power spectrum with high accuracy. As an application, we show that aperturemass observations can be used to constrain ...
متن کاملThe Cosmic Microwave Background: beyond the Power Spectrum
Much recent work on the cosmic microwave background (CMB) has focussed on the angular power spectrum of temperature anisotropies and particularly on the recovery of cosmological parameters from acoustic peaks in the power spectrum. However, there is more that can conceivably be done with CMB measurements. Here I briefly survey a few such ideas: cross-correlation with other cosmic backgrounds as...
متن کاملThe shear power spectrum from the COMBO-17 survey
We perform a statistical weak lensing or “cosmic shear” analysis of the COMBO-17 survey – a unique dataset with shear quality R-band imaging and accurate photometric redshift estimates (σz = 0.05) for ∼ 90% of galaxies to mR ≤ 24.0. We undertake a full maximum likelihood analysis to measure directly from the data the weak lensing power spectra, C l , C ββ l and C l in 5 band powers from l = 400...
متن کاملPower Laws and the Cosmic Ray Energy Spectrum
Two separate statistical tests are applied to the AGASA and preliminary Auger Cosmic Ray Energy spectra in an attempt to find deviation from a pure power-law. The first test is constructed from the probability distribution for the maximum event of a sample drawn from a power-law. The second employs the TP-statistic, a function defined to deviate from zero when the sample deviates from the power...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2015
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/stv2474