English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Based on spectroscopy and multiband wide-field observations of thegravitationally lensed quasar HE 0435-1223, we determine the probabilitydistribution function of the external convergence $\kappa_\mathrm{ext}$ forthis system. We measure the under/overdensity of the line of sight towards thelens system and compare it to the average line of sight throughout theuniverse, determined by using the CFHTLenS as a control field. Aiming toconstrain $\kappa_\mathrm{ext}$ as tightly as possible, we determineunder/overdensities using various combinations of relevant informative weighingschemes for the galaxy counts, such as projected distance to the lens,redshift, and stellar mass. We then convert the measured under/overdensitiesinto a $\kappa_\mathrm{ext}$ distribution, using ray-tracing through theMillennium Simulation. We explore several limiting magnitudes and apertures,and account for systematic and statistical uncertainties relevant to thequality of the observational data, which we further test through simulations.Our most robust estimate of $\kappa_\mathrm{ext}$ has a median value$\kappa^\mathrm{med}_\mathrm{ext} = 0.004$ and a standard deviation of$\sigma_\kappa = 0.025$. The measured $\sigma_\kappa$ corresponds to $2.5\%$uncertainty on the time delay distance, and hence the Hubble constant $H_0$inference from this system. The median $\kappa^\mathrm{med}_\mathrm{ext}$ valueis robust to $\sim0.005$ (i.e. $\sim0.5\%$ on $H_0$) regardless of the adoptedaperture radius, limiting magnitude and weighting scheme, as long as the latterincorporates galaxy number counts, the projected distance to the main lens, anda prior on the external shear obtained from mass modeling. The availability ofa well-constrained $\kappa_\mathrm{ext}$ makes \hequad\ a valuable system formeasuring cosmological parameters using strong gravitational lens time delays.

H0LiCOW III. Quantifying the effect of mass along the line of sight to the gravitational lens HE 0435-1223 through weighted galaxy counts