Threepoint galaxygalaxy lensing as a probe of dark matter halo shapes
Abstract
We propose a method to measure the ellipticities of dark matter halos using the lensshearshear 3point correlation function. This method is immune to effects of galaxyhalo misalignments that can potentially limit 2point galaxygalaxy lensing measurements of halo anisotropy. Using a simple model for the projected mass distributions of dark matter halos, we construct an ellipticity estimator that sums over all possible triangular configurations of the 3point function. By applying our estimator to halos from Nbody simulations, we find that systematic errors in the recovered ellipticity will be at the ∼< 5% fractional level. We estimate that future imaging surveys like LSST will have sufficient statistics to detect halo ellipticities using 3point lensing.
 Authors:
 Department of Astronomy, University of Illinois at UrbanaChampaign, 1002 W. Green Street, Urbana, IL 61810 (United States)
 Publication Date:
 OSTI Identifier:
 22382047
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; CORRELATION FUNCTIONS; ERRORS; GALAXIES; GRAVITATIONAL LENSES; MASS DISTRIBUTION; NONLUMINOUS MATTER; SHAPE; SHEAR; SIMULATION; STATISTICS; TRIANGULAR CONFIGURATION
Citation Formats
Adhikari, Susmita, Chue, Chun Yin Ricky, and Dalal, Neal, Email: sadhika2@illinois.edu, Email: chue2@illinois.edu, Email: dalaln@illinois.edu. Threepoint galaxygalaxy lensing as a probe of dark matter halo shapes. United States: N. p., 2015.
Web. doi:10.1088/14757516/2015/01/009.
Adhikari, Susmita, Chue, Chun Yin Ricky, & Dalal, Neal, Email: sadhika2@illinois.edu, Email: chue2@illinois.edu, Email: dalaln@illinois.edu. Threepoint galaxygalaxy lensing as a probe of dark matter halo shapes. United States. doi:10.1088/14757516/2015/01/009.
Adhikari, Susmita, Chue, Chun Yin Ricky, and Dalal, Neal, Email: sadhika2@illinois.edu, Email: chue2@illinois.edu, Email: dalaln@illinois.edu. 2015.
"Threepoint galaxygalaxy lensing as a probe of dark matter halo shapes". United States.
doi:10.1088/14757516/2015/01/009.
@article{osti_22382047,
title = {Threepoint galaxygalaxy lensing as a probe of dark matter halo shapes},
author = {Adhikari, Susmita and Chue, Chun Yin Ricky and Dalal, Neal, Email: sadhika2@illinois.edu, Email: chue2@illinois.edu, Email: dalaln@illinois.edu},
abstractNote = {We propose a method to measure the ellipticities of dark matter halos using the lensshearshear 3point correlation function. This method is immune to effects of galaxyhalo misalignments that can potentially limit 2point galaxygalaxy lensing measurements of halo anisotropy. Using a simple model for the projected mass distributions of dark matter halos, we construct an ellipticity estimator that sums over all possible triangular configurations of the 3point function. By applying our estimator to halos from Nbody simulations, we find that systematic errors in the recovered ellipticity will be at the ∼< 5% fractional level. We estimate that future imaging surveys like LSST will have sufficient statistics to detect halo ellipticities using 3point lensing.},
doi = {10.1088/14757516/2015/01/009},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 01,
volume = 2015,
place = {United States},
year = 2015,
month = 1
}

Optical imaging surveys measure both the galaxy density and the gravitational lensinginduced shear fields across the sky. Recently, the Dark Energy Survey (DES) collaboration used a joint fit to twopoint correlations between these observables to place tight constraints on cosmology (DES Collaboration et al. 2017). In this work, we develop the methodology to extend the DES Collaboration et al. (2017) analysis to include crosscorrelations of the optical survey observables with gravitational lensing of the cosmic microwave background (CMB) as measured by the South Pole Telescope (SPT) and Planck. Using simulated analyses, we show how the resulting set of five twopointmore »

Semiempirical catalog of earlytype galaxyhalo systems: dark matter density profiles, halo contraction and dark matter annihilation strength
With Sloan Digital Sky Survey galaxy data and halo data from uptodate Nbody simulations within the ΛCDM framework we construct a semiempirical catalog (SEC) of earlytype galaxyhalo systems by making a selfconsistent bivariate statistical match of stellar mass (M{sub *}) and velocity dispersion (σ) with halo virial mass (M{sub vir}) as demonstrated here for the first time. We then assign stellar mass profile and velocity dispersion profile parameters to each system in the SEC using their observed correlations with M{sub *} and σ. Simultaneously, we solve for dark matter density profile of each halo using the spherical Jeans equation. Themore » 
Combining weak lensing tomography with halo clustering to probe dark energy
Two methods of constraining the properties of dark energy are weak lensing tomography and cluster counting. Uncertainties in mass calibration of clusters can be reduced by using the properties of halo clustering (the clustering of clusters). However, within a single survey, weak lensing and halo clustering probe the same density fluctuations. We explore the question of whether this information can be used twiceonce in weak lensing and then again in halo clustering to calibrate cluster massesor whether the combined dark energy constraints are weaker than the sum of the individual constraints. For a survey like the Dark Energy Survey (DES),more » 
NEW CONSTRAINTS ON THE EVOLUTION OF THE STELLARTODARK MATTER CONNECTION: A COMBINED ANALYSIS OF GALAXYGALAXY LENSING, CLUSTERING, AND STELLAR MASS FUNCTIONS FROM z = 0.2 to z = 1
Using data from the COSMOS survey, we perform the first joint analysis of galaxygalaxy weak lensing, galaxy spatial clustering, and galaxy number densities. Carefully accounting for sample variance and for scatter between stellar and halo mass, we model all three observables simultaneously using a novel and selfconsistent theoretical framework. Our results provide strong constraints on the shape and redshift evolution of the stellartohalo mass relation (SHMR) from z = 0.2 to z = 1. At low stellar mass, we find that halo mass scales as M{sub h} {proportional_to}M{sup 0.46}{sub *} and that this scaling does not evolve significantly with redshiftmore » 
Testing dark matter halos using rotation curves and lensing: A warning on the determination of the halo mass
There are two observations of galaxies that can offer some insight into the nature of dark matter (DM), namely, the rotation curves and the gravitational lensing. While the first one can be studied using the Newtonian limit, the second one is completely relativistic. Each one separately cannot determine the nature of DM, but both together give us key information about this open problem. In this work we use a static and spherically symmetric metric to model the DM halo in a galaxy or in a galaxy cluster. The metric contains two free functions, one associated with the distribution of massmore »