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[bug #59726] MakeCatalog's --halfsumradius under estimates effective rad
From: |
Mohammad Akhlaghi |
Subject: |
[bug #59726] MakeCatalog's --halfsumradius under estimates effective radius |
Date: |
Sat, 19 Dec 2020 08:49:55 -0500 (EST) |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:84.0) Gecko/20100101 Firefox/84.0 |
Follow-up Comment #1, bug #59726 (project gnuastro):
Nacho had a good suggestion to see the behavior at Sersic indices below 1 also
(to confirm the hypothesis).
So I updated the input catalog to the one below (the Sersic index is the 6th
column: I also added Sersic index 4), with everything else identical.
1 300 250 1 10 0.5 0 1 1 10
2 700 300 1 10 1 0 1 1 10
4 300 650 1 10 4 0 1 1 10
3 700 700 1 10 10 0 1 1 10
I then ran the same commands before. The resulting image can be seen attached
to this message. Here is the new catalog:
1 8.21
2 8.33
3 8.04
4 5.86
The fact that it hasn't changed between Sersic index of 0.5 and 1 is probably
due to the pixel size limit. It would probably be more clear at larger input
effective radii. But I was expecting a larger difference of measured effective
radius between Sersic index 1 and 4!
I feel that using the elliptical distance instead of pixel counting can
improve this result. Let's see...
(file #50520)
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