DECam Photometric Catalogs of 7 Abell clusters

In Section 2.1 of Kim et al. (in prep), we explained how we evaluated the DECam data that we obtained and used. Here, we present the detailed results of the evaluation. Figure 7 shows the fraction of the mock sources detected by SExtractor as a function of the magnitude for three bands and seven clusters. Table 2 lists magnitudes where the fraction falls below 90% and 1%. As we can see more clearly in Figure 8, mlim,1% of our data 1~2 mag deeper than DECaLS. Table 2 also contains columns of magnitude zero points of the combined images and the surface brightness limits of the r´ band which are over 28 mag/arcsec2 except for A3659.

depth measurement
Figure 6: An example shows how we measured the depth of our DECam data. The original image data is on the left and the image after the addition of mock sources is on the right. The sources within the green circles are detected and the red circles are not detected by SExtractor. We found magnitudes that the detection rates drop below 90% and 1%.
depth measurement
Figure 7: Fractions of mock sources that are recovered by SExtractor. Green solid, blue dashed, grey dotted, and yellow dot-dashed lines are for combined, single, SDSS, and DECaLS images, respectively. The mean and standard deviation among 9, 60, 25, and 25 tiles of combined, single, SDSS, and DECaLS mosaic tiles, respectively, are plotted for each cluster and filter band. We include sources brighter the magnitude where the recovered fraction is getting lower than 1%.
Table 2: Magnitude zero points of the combined images, and completeness and surface brightness limits of the combined, single, SDSS, and DECaLS mosaics for each cluster and filter band
Cluster Filter a´a mlim,90%b mlim,1%c SB100d SB1000e SB2000f
Combined Single SDSS DECaLS Combined Single SDSS DECaLS
A754 u´ 4.21 23.9 23.3 25.8 24.7
g´ 6.38 24.5 24.1 27.3 25.5
r´ 6.61 24.2 23.6 26.8 25.1 28.7 28.3 28.1
A2399 u´ 4.25 24.0 23.6 21.1 26.4 24.9 22.5
g´ 6.16 24.3 23.2 22.1 24.5 27.1 24.5 23.4 26.0
r´ 6.46 24.2 23.6 21.6 23.5 26.9 25.1 23.0 25.0 28.7 28.0 27.8
A2670 u´ 4.06 23.8 23.5 21.0 26.4 24.8 22.4
g´ 6.18 24.6 23.2 22.0 24.2 26.9 24.6 23.8 25.8
r´ 6.28 24.2 23.7 21.5 23.6 27.1 25.4 22.9 25.4 28.8 28.7 28.3
A3558 u´ 4.23 24.0 23.5 26.1 24.8
g´ 6.37 24.7 24.1 26.5 25.5
r´ 6.60 24.1 23.5 27.3 25.1 28.8 28.3 27.9
A3574 u´ 4.19 23.2 23.1 24.8 24.5
g´ 6.41 24.5 24.0 26.4 25.6
r´ 6.60 23.9 23.5 25.9 25.0 28.2 27.9 27.6
A3659 u´ 4.22 23.1 23.1 24.8 24.5
g´ 6.15 23.9 23.7 25.4 25.0
r´ 6.41 23.3 23.5 25.3 24.8 27.5 27.1 27.0
A3716 u´ 4.01 24.1 23.5 25.9 24.8
g´ 6.26 24.6 24.1 24.5 26.8 25.8 26.2
r´ 6.43 24.0 23.8 23.9 26.6 25.3 25.6 28.2 28.0 27.2
Note: (a) Magnitude zero points offsets (from 25) of the combined images, (b) Completeness magnitudes where 90% of mock sources are recovered by SExtractor detection, (c) Completeness magnitudes where 1% of mock sources are recovered by SExtractor detection, (d) Surface brightness limit, the median of standard deviation in moving mesh box 100x100 pixels [mag/ arcsec2], (e) Same as (d) with box size of 1000x1000 pixels, (f) Same as (d) with box size of 2000x2000 pixels
depth measurement
Figure 8: The magnitude ranges where completeness rate drops from 90% (mlim,90%) to 1% mlim,1%). mlim,90% (mlim,1%) is the magnitude where the fraction of the mock sources which are detected by SExtractor falls below 90% (1%). The x-axis is ordered by the number of public data available so it has no physical meaning.

For more information please refer to Kim et al. (in prep), or

Send an email to duhokim81@gmail.com