9 research outputs found
The changing face of European armaments co-operation Continuity and change in British, French and German armaments policy, 1990-2000
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN039937 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Survival, growth and expression of activity of a bacterial inoculant in the rhizoshere
SIGLEAvailable from British Library Document Supply Centre- DSC:DX174250 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Soil macropores and compaction control the leaching potential of Escherichia coli O157:H7
Colloid and Microbe Migration in Granular Environments: A Discussion of Modelling Methods
The Intrinsic Alignment of Red Galaxies in DES Y1 redMaPPer Galaxy Clusters
International audienceClusters of galaxies are sensitive to the most nonlinear peaks in the cosmic density field. The weak gravitational lensing of background galaxies by clusters can allow us to infer their masses. However, galaxies associated with the local environment of the cluster can also be intrinsically aligned due to the local tidal gradient, contaminating any cosmology derived from the lensing signal. We measure this intrinsic alignment in Dark Energy Survey (DES) Year 1 redMaPPer clusters. We find evidence of a non-zero mean radial alignment of galaxies within clusters between redshift 0.1-0.7. We find a significant systematic in the measured ellipticities of cluster satellite galaxies that we attribute to the central galaxy flux and other intracluster light. We attempt to correct this signal, and fit a simple model for intrinsic alignment amplitude () to the measurement, finding , when excluding data near the edge of the cluster. We find a significantly stronger alignment of the central galaxy with the cluster dark matter halo at low redshift and with higher richness and central galaxy absolute magnitude (proxies for cluster mass). This is an important demonstration of the ability of large photometric data sets like DES to provide direct constraints on the intrinsic alignment of galaxies within clusters. These measurements can inform improvements to small-scale modeling and simulation of the intrinsic alignment of galaxies to help improve the separation of the intrinsic alignment signal in weak lensing studies