To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We use the weak gravitational lensing effect to study the mass distribution of a
sample of 50 southern Abell
clusters (0.05 < z < 0.3) having LX > 5 × 1044 erg s-1 observed with ESO-VLT
under uniform sky conditions and subarsecond (0.6'') image quality. Their dynamical
equibrium is assesed through comparison of the clusters mass estimates made by weak-lensing,
velocity-dispersions and X-ray techniques. So far, for 24 clusters (Cypriano
et al. 2004),
we find: a) the center of their mass and light distributions are coincident for
77% of the sample; b) the elongations of the fitted mass profiles and of the light
of the cD galaxies generally match with each other; c) although most
of the clusters are found to be in dynamical equilibrium, those with TX ≥ 8 keV
(or σv ≥ 1120 km s-1) are the discordant ones. The preliminary
bright arc statistics for our whole sample (LZLS) suggests the presence of a
cut-off at z ~ 0.07 which is qualitatively consistent with predictions done
in a ΛCDM cosmology (Meneghetti et al. 2003).
2002–2005 has seen rapid progress in cosmology with the publication of the 1st year WMAP results and analyses of large scale red-shift surveys, ushering in an era of “precision cosmology”. There has been steady progress, too, in the discovery and study of quasars and galaxies in the early Universe.
We report significant associated clustering in the field of a z = 1.226 quasar from the Clowes-Campusano LQG in the form of both a factor ˜ 11 overdensity of I - K > 3.75 galaxies, and red sequences of 15-18 galaxies at I - K ⋍ 4.3, V - K ⋍ 6.9 indicative of a population of massive ellipticals at the quasar redshift. The quasar is located between two groups of these galaxies, with further clustering extending over 2-3 Mpc. A band of V - I < 1 galaxies bisects the two groups of red sequence galaxies, and we suggest that the merging of these two groups has triggered both this band of star-formation and the quasar.