Open AccessHow well can we determine cluster mass profiles from weak lensing?
Author(s) -
Hoekstra Henk
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06264.x
Subject(s) - physics , weak gravitational lensing , astrophysics , gravitational lens , strong gravitational lensing , cluster (spacecraft) , galaxy cluster , line of sight , galaxy , mass distribution , redshift , scale (ratio) , structure formation , computer science , programming language , quantum mechanics
Weak gravitational lensing provides a direct way to study the mass distribution of clusters of galaxies at large radii. Unfortunately, large‐scale structure along the line of sight also contributes to the lensing signal, and consequently affects the measurements. We quantify the effect of distant uncorrelated large‐scale structure on the inferred mass profile of clusters as measured from weak lensing. We consider Navarro, Frenk & White profiles, and find that large‐scale structure is a major source of uncertainty for most practical situations, when a model, with mass M 200 and concentration parameter c as free parameters, is fitted to the observations. We find that the best constraints are found for clusters at intermediate redshifts ( z ≈ 0.3) . For a cluster at z = 0.3 , optimal results are obtained when the lensing signal is measured out to 10–15 arcmin. Measurements at larger radii do not improve the accuracy with which the profile can be determined, contrary to what is expected when the contribution from large‐scale structure is ignored. The true uncertainties in M 200 and the concentration parameter c are ∼2 times larger than when distant large‐scale structure is not included in the error budget.