Effect of Dust in Circumgalactic Halos on the Cosmic Shear Power Spectrum

Abstract Weak gravitational lensing is a powerful statistical tool for probing the growth of cosmic structure and measuring cosmological parameters. However, as shown by studies such Ménard et al., dust in circumgalactic region halos dims reddens background sources. In weak analysis, this selects against sources behind overdense regions; since there more regions, we will underestimate amplitude density perturbations σ 8 if do not correct effects dust. To model distribution employ halo . Assuming fiducial mass profile based on measurements from compute ratio Z systematic error to survey similar Nancy Grace Roman Space Telescope reference (2000 deg 2 area, single-filter effective source 30 galaxies arcmin −2 ). For wave band centered at 1580 nm ( H band), find that = 0.37. with 620 r also computed 2.8. Within our model, > 1, effect be significant image surveys. We bias power spectrum, , found it each Δ / −3.1 × 10 −4 band) or −2.2 −3 all other parameters are held fixed (the forecast statistical-only )/ 9