Mass and Light distributions in Clusters of Galaxies - Henry A ...

3.3 Sample selection from the color-color diagram
2
A1703
10
2
A1703
x 10 −6
7
1.8
1.6
1.4
9
8
1.8
1.6
1.4
6
5
g − r
1.2
1
0.8
7
Radius
g − r
1.2
1
0.8
4
3
Number/pix 2
0.6
6
0.6
2
0.4
5
0.4
1
0.2
0.2
−0.4 −0.2 0 0.2 0.4 0.6 0.8
r − i
−0.4 −0.2 0 0.2 0.4 0.6 0.8
r − i
0
A370
13
A370
x 10 −6
7
2
12
2
6
11
5
B − R
1.5
1
10
9
Radius
B − R
1.5
1
4
3
Number/pix 2
8
2
0.5
7
0.5
6
1
0
−0.4 −0.2 0 0.2 0.4 0.6 0.8 1 1.2
R − Z
0
−0.4 −0.2 0 0.2 0.4 0.6 0.8 1 1.2
R − Z
0
1.4
RXJ1347−11
13
1.4
RXJ1347−11
x 10 −6
7
1.2
12
1.2
6
1
11
1
5
V − R
0.8
0.6
0.4
10
9
8
Radius
V − R
0.8
0.6
0.4
4
3
Number/pix 2
0.2
7
0.2
2
0
6
0
1
−0.2
−0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4
R − Z
5
−0.2
−0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4
R − Z
0
Figure 3.1 – Averaged radius from cluster
center displayed in CC space for A1703,
A370 & RXJ1347-11 (Top to bottom). The
bluer (darker) colors imply average lower
radius, hence correspond to the location of
the cluster in CC space. The black box
marks the boundaries of the green sample
we select, which conservatively includes all
cluster members.
Figure 3.2 – Number density in CC space
for A1703, A370 & RXJ1347-11 (Top to
bottom). The four distinct density peaks
(seen especially in the A370 plot) are shown
to be different galaxy populations - the reddest
peak in the upper right corner of the
plots (dashed white line) depicts the overdensity
of cluster galaxies, whose colors are
lying on the red sequence; the middle peak
with colors bluer than the cluster shows the
overdensity of foreground galaxies; the two
peaks in the bottom part (bluest in B − R)
can be demonstrated to comprise of blue
and red (left and right, respectively) background
galaxies.