Open AccessDetermining cosmological parameters from X‐ray measurements of strong lensing clusters
Author(s) -
Sereno M.,
Longo G.
Publication year - 2004
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 - 10.1111/j.1365-2966.2004.08284.x
Subject(s) - physics , dark energy , astrophysics , equation of state , cosmological constant , galaxy , weak gravitational lensing , galaxy cluster , universe , galaxy groups and clusters , lambda cdm model , hubble's law , cosmology , theoretical physics , redshift , quantum mechanics
We discuss a new method that is potentially capable of constraining cosmological parameters using observations of giant luminous arcs in rich X‐ray clusters of galaxies. The mass profile and the mass normalization of the lenses are determined from X‐ray measurements. The method also allows us to probe the amount and equation of state of the dark energy in the universe. The analysis of a preliminary sample of six luminous, relatively relaxed clusters of galaxies strongly favours an accelerating expansion of the universe. Under the assumption that the dark energy is in the form of a cosmological constant, the data provide an estimate of Ω Λ0 = 1.1 with a statistical error of ±0.2. Including the constraint of a flat universe and an equation of state for the dark energy w X ≥−1 , we obtain Ω M0 = 0.10 ± 0.10 and w X =−0.84 ± 0.14 . Relaxing the prior on w X , we find that the null energy condition (NEC) is satisfied at the 3σ confidence level.