Poster
Abstract
: Strong
lensing (SL) has been employed
extensively to obtain accurate mass
measurements within the Einstein radius,
i.e. at the location of the multiply
imaged systems used as constraints. I
will show that SL can be used to probe
mass distributions on scales much larger
than the one defined by the Einstein
radius. I will discuss this method on
SL2SJ08544-0121, a galaxy group at
redshift z=0.35. This group displays a
bimodal light distribution with a strong
lensing system located at one of the two
luminosity peaks separated by ~54
arcsec. The main arc and the
counter-image of the strong lensing
system are located at ~5 arcsec and ~8
arcsec from the lens galaxy centre. I
will show that a simple elliptical
isothermal potential cannot
satisfactorily reproduce the strong
lensing observations. However, with a
mass model for the group built from its
light-distribution, i obtain an accurate
reproduction of the strong lensing
observations, therefore setting
constraints on the mass of the galaxy
group as a whole. The SL only analysis
hints that we are actually witnessing
the merging of two galaxy groups.
Using complementary data sets,
spectroscopy of galaxy group members and
Xray observations, i will show that the
predictions from the SL only analysis
are confirmed. This kind of analysis
provides a quick and cheap way of
probing the mass distribution of
clusters and groups. This is
particularly relevant in the context of
forthcoming wide field surveys, which
will yield thousands of strong
lenses. |
Bibliography
-
Limousin, M.;
Jullo, E.; Richard, J.; Cabanac, R.;
Suyu, S. H.; Halkola, A.; Kneib,
J.-P.;Gavazzi, R.; Soucail, G.
Strong lensing as a probe of the mass
distribution beyond the Einstein
radius. Mass and light in SL2S
J08544-0121, a galaxy group at z =
0.35
Astron. Astrophys. 524, A95 (2010) ;
ar Xiv: 0906.4118
- Tu,
H.; Limousin, M.; Fort, B.; Shu, C.
G.; Sygnet, J. F.; Jullo, E.; Kneib,
J. P.; Richard, J.
Probing the slope of cluster mass
profile with gravitational Einstein
rings: application to Abell 1689
MNRAS 386,3,1169 (2008) ; arXiv:
0710.2246
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