We present cosmological parameter constraints based on a joint modelling of galaxy–lensing crosscorrelations and galaxy clustering measurements in the SDSS, marginalizing over smallscale modelling uncertainties using mock galaxy catalogues, without explicit modelling of galaxy bias. We show that our modelling method is robust to the impact of different choices for how galaxies occupy dark matter haloes and to the impact of baryonic physics (at the $\sim 2{{\ \rm per\ cent}}$ level in cosmological parameters) and test for the impact of covariance on the likelihood analysis and of the survey window function on the theory computations. Applying our results to the measurements using galaxy samples from BOSS and lensing measurements using shear from SDSS galaxies and CMB lensing from Planck, with conservative scale cuts, we obtain $S_8\equiv \left(\frac{\sigma _8}{0.8228}\right)^{0.8}\left(\frac{\Omega _\mathrm{ m}}{0.307}\right)^{0.6}=0.85\pm 0.05$ (stat.) using LOWZ × SDSS galaxy lensing, and S8 = 0.91 ± 0.1 (stat.) using combination of LOWZ and CMASS × Planck CMB lensing. We estimate the systematic uncertainty in the galaxy–galaxy lensing measurements to be $\sim 6{{\ \rm per\ cent}}$ (dominated by photometric redshift uncertainties) and in the galaxy–CMB lensing measurements to be $\sim 3{{\ \rm per\ cent}}$, from smallscale modelling uncertainties including baryonic physics.
Testing the impact of satellite anisotropy on large and smallscale intrinsic alignments using hydrodynamical simulations
ABSTRACT Galaxy intrinsic alignments (IAs) have long been recognized as a significant contaminant to weak lensingbased cosmological inference. In this paper we seek to quantify the impact of a common modelling assumption in analytic descriptions of IAs: that of spherically symmetric dark matter haloes. Understanding such effects is important as the current generation of IA models are known to be limited, particularly on small scales, and building an accurate theoretical description will be essential for fully exploiting the information in future lensing data. Our analysis is based on a catalogue of 113 560 galaxies between z = 0.06 and 1.00 from massiveblackii, a hydrodynamical simulation of box length $100 \, h^{1}$ Mpc. We find satellite anisotropy contributes at the level of $\ge 30\!\!40{{\ \rm per\ cent}}$ to the smallscale alignment correlation functions. At separations larger than $1 \, h^{1}$ Mpc the impact is roughly scale independent, inducing a shift in the amplitude of the IA power spectra of $\sim 20{{\ \rm per\ cent}}$. These conclusions are consistent across the redshift range and between the massiveblackii and the illustris simulations. The cosmological implications of these results are tested using a simulated likelihood analysis. Synthetic cosmic shear data are constructed with the expected characteristics (depth, area, and more »
 Award ID(s):
 1716131
 Publication Date:
 NSFPAR ID:
 10286738
 Journal Name:
 Monthly Notices of the Royal Astronomical Society
 Volume:
 491
 Issue:
 4
 Page Range or eLocationID:
 5330 to 5350
 ISSN:
 00358711
 Sponsoring Org:
 National Science Foundation
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