The Shapes and Alignments of Dark Matter Halos

Details The Shapes and Alignments of Dark Matter Halos The Shapes and Alignments of Dark Matter Halos

Jan 2012

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012aas...21924809s&link_type=abstract

American Astronomical Society, AAS Meeting #219, #248.09

Astronomy and Astrophysics

Astronomy

Scientific paper

We present measurements of the triaxial dark matter halo shapes and alignment correlation functions in the Millennium and Millennium-2 N-body simulations. We largely confirm previous results on the distributions of halo axis ratios as a function of halo mass, but we show that the median angle between halo major axes at different halo radii can vary by a factor of 2 between the Millennium-1 and 2 simulations because of the different mass resolution. Thus error in the shape determinations from limited resolution is potentially degenerate with the misalignment of halo inner and outer shapes used to constrain BCG alignments in previous works. We also present fits to the 3-D halo-halo and halo-mass alignment correlation functions that are necessary ingredients to triaxial halo models for large-scale structure and models for galaxy intrinsic alignments as contaminants for cosmic shear surveys. We measure strong alignments between halos of all masses and the surrounding dark matter overdensities out to several tens of Megaparsecs, in agreement with observed shear-galaxy and cluster shape correlations. We use these measurements to forecast the contribution to the weak lensing signal around galaxy clusters from correlated mass along the line-of-sight. For prolate clusters with major axes aligned with the line-of-sight the fraction of the weak lensing signal from mass external to the cluster can be twice that predicted if the excess halo alignment correlation is assumed to be zero.

Affiliated with

Also associated with

No associations

Rating

The Shapes and Alignments of Dark Matter Halos does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Shapes and Alignments of Dark Matter Halos, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Shapes and Alignments of Dark Matter Halos will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1579573