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 (10 to 15 for the smallest angular scales) for troughs with the redshift range z in [0.2,0.5] of the projected galaxy field and angular diameters of 10 arcmin...1{\deg}. 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 Lambda cold dark matter model. 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. 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.
Cite
@article{arxiv.1507.05090,
title = {Weak lensing by galaxy troughs in DES Science Verification data},
author = {D. Gruen and O. Friedrich and A. Amara and D. Bacon and C. Bonnett and W. Hartley and B. Jain and M. Jarvis and T. Kacprzak and E. Krause and A. Mana and E. Rozo and E. S. Rykoff and S. Seitz and E. Sheldon and M. A. Troxel and V. Vikram and T. Abbott and F. B. Abdalla and S. Allam and R. Armstrong and M. Banerji and A. H. Bauer and M. R. Becker and A. Benoit-Levy and G. M. Bernstein and R. A. Bernstein and E. Bertin and S. L. Bridle and D. Brooks and E. Buckley-Geer and D. L. Burke and D. Capozzi and A. Carnero Rosell and M. Carrasco Kind and J. Carretero and M. Crocce and C. E. Cunha and C. B. D'Andrea and L. N. da Costa and D. L. DePoy and S. Desai and H. T. Diehl and J. P. Dietrich and P. Doel and T. F. Eifler and A. Fausti Neto and E. Fernandez and B. Flaugher and P. Fosalba and J. Frieman and D. W. Gerdes and R. A. Gruendl and G. Gutierrez and K. Honscheid and D. J. James and K. Kuehn and N. Kuropatkin and O. Lahav and T. S. Li and M. Lima and M. A. G. Maia and M. March and P. Martini and P. Melchior and C. J. Miller and R. Miquel and J. J. Mohr and B. Nord and R. Ogando and A. A. Plazas and K. Reil and A. K. Romer and A. Roodman and M. Sako and E. Sanchez and V. Scarpine and M. Schubnell and I. Sevilla-Noarbe and R. C. Smith and M. Soares-Santos and F. Sobreira and E. Suchyta and M. E. C. Swanson and G. Tarle and J. Thaler and D. Thomas and A. R. Walker and R. H. Wechsler and J. Weller and Y. Zhang and J. Zuntz},
journal= {arXiv preprint arXiv:1507.05090},
year = {2015}
}
Comments
15 pages, 8 figures; matches accepted version; high-resolution versions of figures can be downloaded from http://deswl.github.io