[In all of these pages, "mag bins" of 000, ...925 is shorthand for the parent magnitude bins, where the bin number (100, 650, 825, etc.) is the brighter mag limit of the bin * 100. Thus, "mag bin 725" refers to the mag bin with parents' magnitudes between 7.25 and the lower limit of the next bin, in this case 7.50.]
Some filter glints are located very close to the diffraction spikes. In the past, these glints were not completely caught in the glint processing, but were flagged as spike sources. However, now that we have a very large data set, and will use it to make the diffraction spike widths trace the actual spikes more accurately, we also need to improve the glint parameters to make sure all of the filter glints will be properly flagged.
Since the glint positions do not change with magnitude,
we plotted the data from half of
the 6.0 - 9.25 parent mag bins for each band and hemisphere on one
delx vs. dely scatter plot, which was
"zoomed-in" to allow easy measurements of the positions.
Because one faint known glints were not visible on these plots,
we also had to use a similar scatter plot with all of the south J
parent mag 0.0-6.0 data.
We found that two previously suspected glints,
one each in the north and south H bands,
actually seem to be just part of the bright star halo.
On the other hand, we needed to add two new glints,
one each in the southern hemisphere J and H bands,
which were previously swallowed up in the diffraction spikes;
this brings us to a total of 2, 1, and 2 glints in the J, H, and K bands
in the north and 4, 2, and 2 glints in the south, respectively.
A sample plot is shown below; one of the new glints is
at the bottom of the plot, touching the diffraction spike.
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The glint delx and dely positions were measured from
these plots. We then determined the range of magnitude differences
between the parent and glint sources for each glint.
MAPCOR marks a source as a glint if
it is found within gl_r arcsec of the
glint's expected position (x_par+gl_f, y_par+gl_h),
where (x_par, y_par) is the position of the parent,
and has a magnitude within gl_sigm mag of m_par+gl_delm
where m_par is the magnitude of the parent.
The new glint parameters are found in the tables below,
with all distances in arcsec.
| Northern Hemisphere | |||||
| J Band | H Band | K Band | |||
| glint #1 | glint #2 | glint #1 | glint #1 | glint #2 | |
| gl_f | 1.5 | 3.0 | 1.5 | 1.5 | -4.0 |
| gl_h | -14.0 | -28.5 | -14.0 | -14.0 | 16.5 |
| gl_r | 2.0 | 3.0 | 2.0 | 1.5 | 1.5 |
| gl_delm | 6.7 | 9.0 | 7.9 | 7.8 | 7.2 |
| gl_sigm | 0.9 | 2.0 | 1.6 | 1.8 | 1.3 |
| Southern Hemisphere | ||||||||
| J Band | H Band | K Band | ||||||
| glint #1 | glint #2 | glint #3 | glint #4 | glint #1 | glint #2 | glint #1 | glint #2 | |
| gl_f | -2.5 | 1.0 | -6.5 | -10.0 | -2.5 | 1.0 | -2.5 | 1.0 |
| gl_h | 11.0 | -13.5 | 22.0 | 33.5 | 11.5 | -13.5 | 11.0 | -13.5 |
| gl_r | 3.0 | 1.5 | 3.5 | 5.0 | 3.0 | 1.5 | 3.0 | 2.0 |
| gl_delm | 6.5 | 9.0 | 9.0 | 12.0 | 8.0 | 8.2 | 7.3 | 7.5 |
| gl_sigm | 1.0 | 2.0 | 2.5 | 3.0 | 2.0 | 2.0 | 2.4 | 1.5 |
Return to the parameter tuning page.
Go to the diffraction spike length page.
Go to the diffraction spike width page.
Go to the confusion radius page.