39 research outputs found
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Dark Energy Survey Year 1 Results: Cross-correlation between Dark Energy Survey Y1 galaxy weak lensing and South Pole Telescope +Planck CMB weak lensing
We cross-correlate galaxy weak lensing measurements from the Dark Energy Survey (DES) year-one data with a cosmic microwave background (CMB) weak lensing map derived from South Pole Telescope (SPT) and Planck data, with an effective overlapping area of 1289 deg2. With the combined measurements from four source galaxy redshift bins, we obtain a detection significance of 5.8σ. We fit the amplitude of the correlation functions while fixing the cosmological parameters to a fiducial ΛCDM model, finding A=0.99±0.17. We additionally use the correlation function measurements to constrain shear calibration bias, obtaining constraints that are consistent with previous DES analyses. Finally, when performing a cosmological analysis under the ΛCDM model, we obtain the marginalized constraints of ωm=0.261-0.051+0.070 and S8σ8ωm/0.3=0.660-0.100+0.085. These measurements are used in a companion work that presents cosmological constraints from the joint analysis of two-point functions among galaxies, galaxy shears, and CMB lensing using DES, SPT, and Planck data
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Dark Energy Survey year 1 results: Joint analysis of galaxy clustering, galaxy lensing, and CMB lensing two-point functions
We perform a joint analysis of the auto and cross-correlations between three
cosmic fields: the galaxy density field, the galaxy weak lensing shear field,
and the cosmic microwave background (CMB) weak lensing convergence field. These
three fields are measured using roughly 1300 sq. deg. of overlapping optical
imaging data from first year observations of the Dark Energy Survey and
millimeter-wave observations of the CMB from both the South Pole Telescope
Sunyaev-Zel'dovich survey and Planck. We present cosmological constraints from
the joint analysis of the two-point correlation functions between galaxy
density and galaxy shear with CMB lensing. We test for consistency between
these measurements and the DES-only two-point function measurements, finding no
evidence for inconsistency in the context of flat CDM cosmological
models. Performing a joint analysis of five of the possible correlation
functions between these fields (excluding only the CMB lensing autospectrum)
yields and . We test
for consistency between these five correlation function measurements and the
Planck-only measurement of the CMB lensing autospectrum, again finding no
evidence for inconsistency in the context of flat CDM models.
Combining constraints from all six two-point functions yields
and .
These results provide a powerful test and confirmation of the results from the
first year DES joint-probes analysis
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Cosmological lensing ratios with des Y1, SPT, and Planck
Correlations between tracers of the matter density field and gravitational lensing are sensitive to the evolution of the matter power spectrum and the expansion rate across cosmic time. Appropriately defined ratios of such correlation functions, on the other hand, depend only on the angular diameter distances to the tracer objects and to the gravitational lensing source planes. Because of their simple cosmological dependence, such ratios can exploit available signal-to-noise ratio down to small angular scales, even where directly modelling the correlation functions is difficult. We present a measurement of lensing ratios using galaxy position and lensing data from the Dark Energy Survey, and CMB lensing data from the South Pole Telescope and Planck, obtaining the highest precision lensing ratio measurements to date. Relative to the concordance CDM model, we find a best-fitting lensing ratio amplitude of A = 1.1 ± 0.1. We use the ratio measurements to generate cosmological constraints, focusing on the curvature parameter. We demonstrate that photometrically selected galaxies can be used to measure lensing ratios, and argue that future lensing ratio measurements with data from a combination of LSST and Stage-4 CMB experiments can be used to place interesting cosmological constraints, even after considering the systematic uncertainties associated with photometric redshift and galaxy shear estimation
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Dark Energy Survey Year 1 Results: Tomographic cross-correlations between Dark Energy Survey galaxies and CMB lensing from South Pole Telescope+Planck
We measure the cross-correlation between redMaGiC galaxies selected from the Dark Energy Survey (DES) year 1 data and gravitational lensing of the cosmic microwave background (CMB) reconstructed from South Pole Telescope (SPT) and Planck data over 1289 deg2. When combining measurements across multiple galaxy redshift bins spanning the redshift range of 0.1
Evidence that the Ceratobasidium-like white-thread blight and black rot fungal pathogens from persimmon and tea crops in the Brazilian Atlantic Forest agroecosystem are two distinct phylospecies
The white-thread blight and black rot (WTBR) caused by basidiomycetous fungi of the genus Ceratobasidium is emerging as an important plant disease in Brazil, particularly for crop species in the Ericales such as persimmon (Diospyros kaki) and tea (Camellia sinensis). However, the species identity of the fungal pathogen associated with either of these hosts is still unclear. In this work, we used sequence variation in the internal transcribed spacer regions, including the 5.8S coding region of rDNA (ITS-5.8S rDNA), to determine the phylogenetic placement of the local white-thread-blight-associated populations of Ceratobasidium sp. from persimmon and tea, in relation to Ceratobasidium species already described world-wide. The two sister populations of Ceratobasidium sp. from persimmon and tea in the Brazilian Atlantic Forest agroecosystem most likely represent distinct species within Ceratobasidium and are also distinct from C. noxium, the etiological agent of the first description of white-thread blight disease that was reported on coffee in India. The intraspecific variation for the two Ceratobasidium sp. populations was also analyzed using three mitochondrial genes (ATP6, nad1 and nad2). As reported for other fungi, variation in nuclear and mitochondrial DNA was incongruent. Despite distinct variability in the ITS-rDNA region these two populations shared similar mitochondrial DNA haplotypes
Cosmological lensing ratios with DES Y1, SPT and Planck
International audienceCorrelations between tracers of the matter density field and gravitational lensing are sensitive to the evolution of the matter power spectrum and the expansion rate across cosmic time. Appropriately defined ratios of such correlation functions, on the other hand, depend only on the angular diameter distances to the tracer objects and to the gravitational lensing source planes. Because of their simple cosmological dependence, such ratios can exploit available signal-to-noise ratio down to small angular scales, even where directly modelling the correlation functions is difficult. We present a measurement of lensing ratios using galaxy position and lensing data from the Dark Energy Survey, and CMB lensing data from the South Pole Telescope and Planck, obtaining the highest precision lensing ratio measurements to date. Relative to the concordance ΛCDM model, we find a best-fitting lensing ratio amplitude of A = 1.1 ± 0.1. We use the ratio measurements to generate cosmological constraints, focusing on the curvature parameter. We demonstrate that photometrically selected galaxies can be used to measure lensing ratios, and argue that future lensing ratio measurements with data from a combination of LSST and Stage-4 CMB experiments can be used to place interesting cosmological constraints, even after considering the systematic uncertainties associated with photometric redshift and galaxy shear estimation
Dark Energy Survey Year 1 Results:tomographic cross-correlations between DES galaxies and CMB lensing from SPT+Planck
International audienceWe measure the cross-correlation between redMaGiC galaxies selected from the Dark Energy Survey (DES) year 1 data and gravitational lensing of the cosmic microwave background (CMB) reconstructed from South Pole Telescope (SPT) and Planck data over 1289 deg2. When combining measurements across multiple galaxy redshift bins spanning the redshift range of 0.15<z<0.90, we reject the hypothesis of no correlation at 19.9σ significance. When removing small-scale data points where thermal Sunyaev-Zel’dovich signal and nonlinear galaxy bias could potentially bias our results, the detection significance is reduced to 9.9σ. We perform a joint analysis of galaxy-CMB lensing cross-correlations and galaxy clustering to constrain cosmology, finding Ωm=0.276-0.030+0.029 and S8=σ8Ωm/0.3=0.800-0.094+0.090. We also perform two alternate analyses aimed at constraining only the growth rate of cosmic structure as a function of redshift, finding consistency with predictions from the concordance ΛCDM model. The measurements presented here are part of a joint cosmological analysis that combines galaxy clustering, galaxy lensing and CMB lensing using data from DES, SPT and Planck