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Title: Weak Lensing by Galaxy Troughs in DES Science Verification Data

Abstract

We measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ϵ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers of the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. Furthermore, the prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on allmore » scales. Finally, the lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.« less

Authors:
 [1]
  1. Ludwig Maximilian Univ., Munich (Germany); Max Planck Inst. for Extraterrestrial Physics, Garching (Germany). et al.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Org.:
DES Collaboration
OSTI Identifier:
1223229
Report Number(s):
FERMILAB-PUB-15-300-AE
Journal ID: ISSN 1365-2966; arXiv eprint number arXiv:1507.05090
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article
Journal Name:
Monthly Notices of the Royal Astronomical Society (Online)
Additional Journal Information:
Journal Volume: 455; Journal Issue: 3; Journal ID: ISSN 1365-2966
Publisher:
Royal Astronomical Society
Country of Publication:
United States
Language:
English
Subject:
gravitational lensing: weak; cosmology: observations

Citation Formats

Gruen, D. Weak Lensing by Galaxy Troughs in DES Science Verification Data. United States: N. p., 2015. Web. doi:10.1093/mnras/stv2506.
Gruen, D. Weak Lensing by Galaxy Troughs in DES Science Verification Data. United States. doi:10.1093/mnras/stv2506.
Gruen, D. Tue . "Weak Lensing by Galaxy Troughs in DES Science Verification Data". United States. doi:10.1093/mnras/stv2506.
@article{osti_1223229,
title = {Weak Lensing by Galaxy Troughs in DES Science Verification Data},
author = {Gruen, D.},
abstractNote = {We measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ϵ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers of the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. Furthermore, the prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. Finally, the lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.},
doi = {10.1093/mnras/stv2506},
journal = {Monthly Notices of the Royal Astronomical Society (Online)},
issn = {1365-2966},
number = 3,
volume = 455,
place = {United States},
year = {2015},
month = {9}
}