868 research outputs found

    The Weak Lensing Signal and the Clustering of BOSS Galaxies I: Measurements

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    A joint analysis of the clustering of galaxies and their weak gravitational lensing signal is well-suited to simultaneously constrain the galaxy-halo connection as well as the cosmological parameters by breaking the degeneracy between galaxy bias and the amplitude of clustering signal. In a series of two papers, we perform such an analysis at the highest redshift (z∌0.53z\sim0.53) in the literature using CMASS galaxies in the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey Eleventh Data Release (SDSS-III/BOSS DR11) catalog spanning 8300~deg2^2. In this paper, we present details of the clustering and weak lensing measurements of these galaxies. We define a subsample of 400,916 CMASS galaxies based on their redshifts and stellar mass estimates so that the galaxies constitute an approximately volume-limited and similar population over the redshift range 0.47≀z≀0.590.47\le z\le 0.59. We obtain a signal-to-noise ratio S/N≃56S/N\simeq 56 for the galaxy clustering measurement. We also explore the redshift and stellar mass dependence of the clustering signal. For the weak lensing measurement, we use existing deeper imaging data from the CFHTLS with publicly available shape and photometric redshift catalogs from CFHTLenS, but only in a 105~deg2^2 area which overlaps with BOSS. This restricts the lensing measurement to only 5,084 CMASS galaxies. After careful systematic tests, we find a highly significant detection of the CMASS weak lensing signal, with total S/N≃26S/N\simeq 26. These measurements form the basis of the halo occupation distribution and cosmology analysis presented in More et al. (Paper II).Comment: 15 pages, 13 figures. Accepted for publication in the Astrophysical Journa

    Coexistence of α+α+n+n and α+t+t cluster structures in 10Be

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    The coexistence of the α+α+n+n and α+t+t cluster structures in the excited states of 10Be has been discussed. In the previous analysis, all the low-lying states of 10Be were found to be well described by the motion of the two valence neutrons around two α clusters. However, the α+t+t cluster structure was found to coexist with the α+α+n+n structure around Ex=15 MeV, close to the corresponding threshold. We have introduced a microscopic model to solve the coupling effect between these two configurations. The K=0 and K=1 states are generated from the α+t+t configurations due to the spin coupling of two triton clusters. The present case of 10Be is one of the few examples in which completely different configurations of triton-type (α+t+t three-center) and α-type (α+α+n+n two-center) clusters coexist in a single nucleus in the same energy region

    Synthesis, Stability, and Crystal Structure of an Azulenium Cation Containing an Adamantyl Group

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    This is the pre-peer reviewed version of the following article: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. 2008(31):5301-5307 (2008), which has been published in final form at doi:10.1002/ejoc.200800700.ArticleEUROPEAN JOURNAL OF ORGANIC CHEMISTRY. 2008(31):5301-5307 (2008)journal articl

    Planck Sunyaev-Zel'dovich Cluster Mass Calibration using Hyper Suprime-Cam Weak Lensing

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    Using ∌\sim140 deg2^2 Subaru Hyper Suprime-Cam (HSC) survey data, we stack the weak lensing (WL) signal around five Planck clusters found within the footprint. This yields a 15σ\sigma detection of the mean Planck cluster mass density profile. The five Planck clusters span a relatively wide mass range, MWL,500c=(2−30)×1014 M⊙/hM_{\rm WL,500c} = (2-30)\times10^{14}\,M_\odot/h with a mean mass of MWL,500c=(4.15±0.61)×1014 M⊙/hM_{\rm WL,500c} = (4.15\pm0.61)\times10^{14}\,M_\odot/h. The ratio of the stacked Planck Sunyaev-Zel'dovich (SZ) mass to the stacked WL mass is ⟹MSZ⟩/⟹MWL⟩=1−b=0.80±0.14 \langle M_{\rm SZ}\rangle/\langle M_{\rm WL}\rangle = 1-b = 0.80\pm0.14. This mass bias is consistent with previous WL mass calibrations of Planck clusters within the errors. We discuss the implications of our findings for the calibration of SZ cluster counts and the much discussed tension between Planck SZ cluster counts and Planck Λ\LambdaCDM cosmology.Comment: 12 pages, 2 tables, 7 figures, accepted to PASJ special issu

    Looking through the same lens: Shear calibration for LSST, Euclid, and WFIRST with stage 4 CMB lensing

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    The next-generation weak lensing surveys (i.e., LSST, Euclid, and WFIRST) will require exquisite control over systematic effects. In this paper, we address shear calibration and present the most realistic forecast to date for LSST/Euclid/WFIRST and CMB lensing from a stage 4 CMB experiment (“CMB S4”). We use the cosmolike code to simulate a joint analysis of all the two-point functions of galaxy density, galaxy shear, and CMB lensing convergence. We include the full Gaussian and non-Gaussian covariances and explore the resulting joint likelihood with Monte Carlo Markov chains. We constrain shear calibration biases while simultaneously varying cosmological parameters, galaxy biases, and photometric redshift uncertainties. We find that CMB lensing from CMB S4 enables the calibration of the shear biases down to 0.2%–3% in ten tomographic bins for LSST (below the ∌ 0.5 % requirements in most tomographic bins), down to 0.4%–2.4% in ten bins for Euclid, and 0.6%–3.2% in ten bins for WFIRST. For a given lensing survey, the method works best at high redshift where shear calibration is otherwise most challenging. This self-calibration is robust to Gaussian photometric redshift uncertainties and to a reasonable level of intrinsic alignment. It is also robust to changes in the beam and the effectiveness of the component separation of the CMB experiment, and slowly dependent on its depth, making it possible with third-generation CMB experiments such as AdvACT and SPT-3G, as well as the Simons Observatory
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