NED Abstract 
Copyright by European Southern Observatory (ESO).
Reproduced by permission

2004A&A...422..407G

Mass and light in the supercluster of galaxies MS0302+17 

R. Gavazzi, Y. Mellier, B. Fort, J.-C. Cuillandre and M. Dantel-Fort 

Received 20 January 2004 / Accepted 8 April 2004 

We investigate the supercluster MS0302+17 (z ~ 0.42) using weak lensing
analysis and deep wide field BVR photometry with the CFH12K camera.
Using (B-V) vs. (V-R) evolution tracks we identify early-type members of
the supercluster, and foreground ellipticals. We derive a R band catalogue
of background galaxies for weak lensing analysis. We compute the
correlation functions of light and mass and their cross-correlation and
test if light traces mass on supercluster, cluster and galaxy scales.
   We show that the data are consistent with this assertion. The
{zeta}-statistic applied in regions close to cluster centers and global
correlation analyses over the whole field converge toward the simple
relation M/L = 300 +/- 30,h_70_,(M/L)_sun_ in the B band. This
independently confirms the earlier results obtained by Kaiser et al.
(1998).
   If we model dark matter halos around each early-type galaxy by a 
truncated isothermal sphere, we find that a linear relation M is 
proportional to L still holds. In this case, the average halo truncation 
radius is s_* ~< 200h^-1^_70_,kpc close to clusters cores whereas it 
reaches a lower limit of 300h^-1^_70_,kpc at the periphery. This change of 
s_*_ as a function of radial distance may be interpreted as a result of 
tidal stripping of early type galaxies. Nevertheless the lack of 
information  on the spatial distribution of late-type galaxies affects such 
conclusions  concerning variations of s_*_.
   Though all the data at hand are clearly consistent with the assumption 
that mass is faithfully traced by light from early-type galaxies, we are 
not able to describe in detail the contribution of late type galaxies. We
however found it to be small. Forthcoming wide surveys in UV, visible, and
near infrared wavelengths will provide large enough samples to extend this
analysis to late-type galaxies using photometric redshifts. 

Keywords: cosmology: large-scale structure of Universe, gravitational
lensing, cosmology: dark matter