The Effects of Halotohalo Variation on Substructure Lensing
Abstract
We explore the halotohalo variation of dark matter (DM) substructure in galaxysized DM halos, focusing on its implications for strongly gravitational lensed systems. We find that the median value for projected substructure mass fractions within projected radii of 3% of the host halo virial radius is approximately f _{sub} ≈ 0.25%, but that the variance is large with a 95 percentile range of 0 <= f _{sub} <= 1%. We quantify possible effects of substructure on quadruply imaged lens systems using the cusp relation and the simple statistic, R _{cusp}. We estimate that the probability of obtaining the large values of the R _{cusp} which have been observed from substructure effects is roughly ~10^{3} to ~10^{2}. We consider a variety of possible correlations between host halo properties and substructure properties in order to probe possible sample biases. In particular, lowconcentration host DM halos have more large substructures and give rise to large values of R _{cusp} more often. However, there is no known observational bias that would drive observed quadruply imaged quasars to be produced by lowconcentration lens halos. Finally, we show that the substructure mass fraction is a relatively reliable predictor of the value of R _{cusp}.
 Publication:

The Astrophysical Journal
 Pub Date:
 November 2011
 DOI:
 10.1088/0004637X/741/2/117
 arXiv:
 arXiv:1101.2916
 Bibcode:
 2011ApJ...741..117C
 Keywords:

 cosmology: theory;
 dark matter;
 galaxies: halos;
 gravitational lensing: strong;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 14 pages, 10 figures. Replaced with version accepted for publication in ApJ. Minor changes from version 1